[mobile] Match feature switch defaults with SDK

[vitek-karas]

E.g. Event source support is disabled by default by the iOS and Android SDKs, and ideally, we should match that behavior as closely as possible in general runtime functionality.

This PR matches the feature switch defaults to the ones in iOS/Android SDKs.

[dotnet-policy-service]

Tagging subscribers to 'arch-android': @vitek-karas, @simonrozsival, @steveisok, @akoeplinger
See info in area-owners.md if you want to be subscribed.

[akoeplinger]

We already have this code which sets the ~same default for testing:

runtime/eng/testing/tests.mobile.targets

Lines 34 to 40 in f402418

	<!-- Reduce library test app size by trimming framework library features -->
	<DebuggerSupport Condition="'$(DebuggerSupport)' == '' and '$(Configuration)' != 'Debug'">false</DebuggerSupport>
	<EnableUnsafeUTF7Encoding Condition="'$(EnableUnsafeUTF7Encoding)' == ''">false</EnableUnsafeUTF7Encoding>
	<EventSourceSupport Condition="'$(EventSourceSupport)' == ''">false</EventSourceSupport>
	<HttpActivityPropagationSupport Condition="'$(HttpActivityPropagationSupport)' == ''">false</HttpActivityPropagationSupport>
	<UseSystemResourceKeys Condition="'$(UseSystemResourceKeys)' == ''">false</UseSystemResourceKeys>
	<UseNativeHttpHandler Condition="'$(UseNativeHttpHandler)' == ''">false</UseNativeHttpHandler>

Would be nice to move this to extract this into a common .targets that we can import into the samples apps.
Browser/wasm sample apps have the same issue.

[matouskozak]

We already have this code which sets the ~same default for testing:

runtime/eng/testing/tests.mobile.targets

Lines 34 to 40 in f402418

	<!-- Reduce library test app size by trimming framework library features -->
	<DebuggerSupport Condition="'$(DebuggerSupport)' == '' and '$(Configuration)' != 'Debug'">false</DebuggerSupport>
	<EnableUnsafeUTF7Encoding Condition="'$(EnableUnsafeUTF7Encoding)' == ''">false</EnableUnsafeUTF7Encoding>
	<EventSourceSupport Condition="'$(EventSourceSupport)' == ''">false</EventSourceSupport>
	<HttpActivityPropagationSupport Condition="'$(HttpActivityPropagationSupport)' == ''">false</HttpActivityPropagationSupport>
	<UseSystemResourceKeys Condition="'$(UseSystemResourceKeys)' == ''">false</UseSystemResourceKeys>
	<UseNativeHttpHandler Condition="'$(UseNativeHttpHandler)' == ''">false</UseNativeHttpHandler>

Would be nice to move this to extract this into a common .targets that we can import into the samples apps. Browser/wasm sample apps have the same issue.

What kind of feature switches would Browser/wasm sample apps want to turn off/on?

For mobile sample apps, I think it would make sense to set an intersection of Android https://github.com/dotnet/android/blob/119d46c3a424ffeb3721718043616bfb10f5622f/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.DefaultProperties.targets#L109-L120 and macios https://github.com/xamarin/xamarin-macios/blob/92092f67fdc0979b9db95bdef55a9c8280d383e4/dotnet/targets/Xamarin.Shared.Sdk.targets#L121-L136 settings.

E.g.:

<EnableUnsafeBinaryFormatterSerialization Condition="'$(EnableUnsafeBinaryFormatterSerialization)' == ''">false</EnableUnsafeBinaryFormatterSerialization>
<EnableUnsafeUTF7Encoding Condition="'$(EnableUnsafeUTF7Encoding)' == ''">false</EnableUnsafeUTF7Encoding>
<EventSourceSupport Condition="'$(EventSourceSupport)' == ''">false</EventSourceSupport>
<HttpActivityPropagationSupport Condition="'$(HttpActivityPropagationSupport)' == ''">false</HttpActivityPropagationSupport>
<InvariantGlobalization Condition="'$(InvariantGlobalization)' == ''">false</InvariantGlobalization>
<StartupHookSupport Condition="'$(StartupHookSupport)' == ''">false</StartupHookSupport>
<UseNativeHttpHandler Condition="'$(UseNativeHttpHandler)' == ''">true</UseNativeHttpHandler>

[ivanpovazan]

I agree with @akoeplinger
Probably we can make use of this file: https://github.com/dotnet/runtime/blob/main/src/mono/msbuild/common/CommonMobileBuild.props

[stephentoub]

@vitek-karas, should this PR be merged or closed?

[davidnguyen-tech]

From what I understood, the goal here was to match feature switch defaults to the ones in iOS/Android SDKs.

For that reason, I chose to copy-paste the SDKs defaults into AppleBuild.props and AndroidBuild.props, as it should be easier to maintain than using CommonMobileBuilds.props that was proposed earlier.

EDIT: CommonMobileBuilds.props is actually Mono-specific https://github.com/dotnet/runtime/pull/111545/files#r1933751217

[davidnguyen-tech]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[davidnguyen-tech]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[davidnguyen-tech]

Observation from the runtime pipeline: Some mobile tests start to fail because of some FileNotFound exceptions.

• android-x64 Release AllSubsets_CoreCLR: `System.IO.FileNotFoundException:

...
[FAIL] System.Net.WebSockets.Client.Tests.CloseTest_Invoker_Http2Loopback.CloseOutputAsync_ServerInitiated_CanSend(useSsl: False)
                 09-24 10:17:12.231  4138  7982 I DOTNET  : System.IO.FileNotFoundException : Could not load file or assembly 'Mono.Android, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
                 09-24 10:17:12.231  4138  7982 I DOTNET  :    at System.Reflection.RuntimeAssembly.<InternalLoad>g____PInvoke|48_0(NativeAssemblyNameParts* __pAssemblyNameParts_native, ObjectHandleOnStack __requestingAssembly_native, StackCrawlMarkHandle __stackMark_native, Int32 __throwOnFileNotFound_native, ObjectHandleOnStack __assemblyLoadContext_native, ObjectHandleOnStack __retAssembly_native)
...

• maccatalyst-x64 Release AllSubsets_Mono:

...
[FAIL] System.IO.Tests.FileNotFoundExceptionTests.ToStringTest   Test name: System.IO.Tests.FileNotFoundExceptionTests.ToStringTest
[05:14:39] dbug: Assembly:  [System.Runtime.Tests, Version=10.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51]
[05:14:39] dbug: 2025-09-24 05:14:22.052 Df System.Runtime.Tests[11650:30122]    Exception messages: Assert.Contains() Failure: Sub-string not found
[05:14:39] dbug: String:    "System.IO.FileNotFoundException: this is "···
[05:14:39] dbug: Not found: ": 'file.txt'"   Exception stack traces:    at System.IO.Tests.FileNotFoundExceptionTests.ToStringTest()
...

• maccatalyst-arm64 Release AllSubsets_Mono: similar as x64

[kotlarmilos]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).