fix: Match the client's Xamarin.Android.Support.v4 package Android pr…

…oject (#198)

The support package used by the client's `.csproj` was a slightly
different version than what is used in the Android test project.

I've matched it to the Android project and the `build_android_and_ios`
succeeds.

src/LaunchDarkly.ClientSdk/LaunchDarkly.ClientSdk.csproj

@@ -95,13 +95,13 @@
     </Compile>
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'monoandroid71'">
-    <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.3" />
+    <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.1" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'monoandroid80'">
-    <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.3" />
+    <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.1" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'monoandroid81'">
-    <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.3" />
+    <PackageReference Include="Xamarin.Android.Support.v4" Version="28.0.0.1" />
   </ItemGroup>
   <PropertyGroup Condition="'$(Configuration)'=='Release'">
     <AssemblyOriginatorKeyFile>../../LaunchDarkly.ClientSdk.snk</AssemblyOriginatorKeyFile>