Add more documentation.

Author: jpobst

Documentation/guides/building-apps/build-items.md

@@ -14,6 +14,23 @@ ms.date: 07/26/2022
 Build items control how a Xamarin.Android application
 or library project is built.
 
+## AndroidAdditionalJavaManifest
+
+`<AndroidAdditionalJavaManifest>` is used in conjunction with [Java Dependency Resolution](../JavaDependencyVerification.md).
+
+It is used to specify additional POM files that will be needed to verify dependencies.
+These are often parent or imported POM files referenced by a Java library's POM file.
+
+```xml
+<ItemGroup>
+  <AndroidAdditionalJavaManifest Include="mylib-parent.pom" JavaArtifact="com.example.mylib-parent" JavaVersion="1.0.0" />
+</ItemGroup>
+```
+See the [Java Dependency Resolution documentation](../JavaDependencyVerification.md)
+for more details.
+
+This build action was introduced in .NET 9.
+
 ## AndroidAsset
 
 Supports [Android Assets](https://developer.android.com/guide/topics/resources/providing-resources#OriginalFiles),
@@ -84,6 +101,25 @@ Files with a Build action of `AndroidJavaLibrary` are Java
 Archives ( `.jar` files) that will be included in the final Android
 package.
 
+## AndroidIgnoredJavaDependency
+
+`<AndroidIgnoredJavaDependency>` is used in conjunction with [Java Dependency Resolution](../JavaDependencyVerification.md).
+
+It is used to specify a Java dependency that should be ignored. This can be
+used if a dependency will be fulfilled in a way that Java dependency resolution
+cannot detect.
+
+```xml
+<!-- Include format is {GroupId}:{ArtifactId} -->
+<ItemGroup>
+  <AndroidIgnoredJavaDependency Include="com.google.errorprone:error_prone_annotations" Version="2.15.0" />
+</ItemGroup>
+```
+See the [Java Dependency Resolution documentation](../JavaDependencyVerification.md)
+for more details.
+
+This build action was introduced in .NET 9.
+
 ## AndroidJavaSource
 
 Files with a Build action of `AndroidJavaSource` are Java source code that

Documentation/guides/messages/README.md

@@ -183,6 +183,19 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + XA4230: Error parsing XML: {exception}
 + [XA4231](xa4231.md): The Android class parser value 'jar2xml' is deprecated and will be removed in a future version of Xamarin.Android. Update the project properties to use 'class-parse'.
 + [XA4232](xa4232.md): The Android code generation target 'XamarinAndroid' is deprecated and will be removed in a future version of Xamarin.Android. Update the project properties to use 'XAJavaInterop1'.
++ [XA4234](xa4234.md): '<{item}>' item '{itemspec}' is missing required attribute '{name}'.
++ [XA4235](xa4235.md): Maven artifact specification '{artifact}' is invalid. The correct format is 'group_id:artifact_id'.
++ [XA4236](xa4236.md): Cannot download Maven artifact '{group}:{artifact}'. - {jar}: {exception} - {aar}: {exception}
++ [XA4237](xa4237.md): Cannot download POM file for Maven artifact '{artifact}'. - {exception}
++ [XA4239](xa4239.md): Unknown Maven repository: '{repository}'.
++ [XA4241](xa4241.md): Java dependency '{artifact}' is not satisfied.
++ [XA4242](xa4242.md): Java dependency '{artifact}' is not satisfied. Microsoft maintains the NuGet package '{nugetId}' that could fulfill this dependency.
++ [XA4243](xa4243.md): Attribute '{name}' is required when using '{name}' for '{element}' item '{itemspec}'.
++ [XA4244](xa4244.md): Attribute '{name}' cannot be empty for '{element}' item '{itemspec}'.
++ [XA4245](xa4245.md): Specified POM file '{file}' does not exist.
++ [XA4246](xa4246.md): Could not parse POM file '{file}'. - {exception}
++ [XA4247](xa4247.md): Could not resolve POM file for artifact '{artifact}'.
++ [XA4248](xa4248.md): Could not find NuGet package '{nugetId}' version '{version}' in lock file. Ensure NuGet Restore has run since this <PackageReference> was added.
 + XA4300: Native library '{library}' will not be bundled because it has an unsupported ABI.
 + [XA4301](xa4301.md): Apk already contains the item `xxx`.
 + [XA4302](xa4302.md): Unhandled exception merging \`AndroidManifest.xml\`: {ex}