Support Fast Deployment of @(AndroidEnvironment)

[jonpryor]

Android framework version

net9.0-android

Affected platform version

.NET 9

Description

Feature Request: support fast deployment of @(AndroidEnvironment) entries. This is primarily to assist Aspire, which like environment variables which constantly change, so our thinking is that if we supported fast deployment of @(AndroidEnvironment), then Aspire could just use an @(AndroidEnvironment) file(s) and the Install target, and we'd make things performant by not constantly rebuilding the .apk.

• Update xamarin/monodroid to fast deploy @(AndroidEnvironment) to e.g. files/.__override__/env/*.txt
• Update dotnet/android to read files/.__override__/env/*.txt during app startup.

Unspecified is where the env/*.txt files should be read. libmono-android*.so is an obvious place, but increases the amount of C++ code we have hanging around. I'm partial to JNIEnvInit.Initialize():

android/src/Mono.Android/Android.Runtime/JNIEnvInit.cs

Lines 81 to 118 in d101851

	[UnmanagedCallersOnly]
	internal static unsafe void Initialize (JnienvInitializeArgs* args)
	{
	IntPtr total_timing_sequence = IntPtr.Zero;
	IntPtr partial_timing_sequence = IntPtr.Zero;
	LogAssemblyCategory = (args->logCategories & (uint)LogCategories.Assembly) != 0;
	gref_gc_threshold = args->grefGcThreshold;
	jniRemappingInUse = args->jniRemappingInUse;
	MarshalMethodsEnabled = args->marshalMethodsEnabled;
	java_class_loader = args->grefLoader;
	mid_Class_forName = new JniMethodInfo (args->Class_forName, isStatic: true);
	bool androidNewerThan10 = args->androidSdkVersion > 10;
	BoundExceptionType = (BoundExceptionType)args->ioExceptionType;
	androidRuntime = new AndroidRuntime (args->env, args->javaVm, androidNewerThan10, args->grefLoader, args->Loader_loadClass, args->jniAddNativeMethodRegistrationAttributePresent != 0);
	AndroidValueManager = (AndroidValueManager) androidRuntime.ValueManager;
	AllocObjectSupported = androidNewerThan10;
	IsRunningOnDesktop = args->isRunningOnDesktop == 1;
	grefIGCUserPeer_class = args->grefIGCUserPeer;
	PropagateExceptions = args->brokenExceptionTransitions == 0;
	JavaNativeTypeManager.PackageNamingPolicy = (PackageNamingPolicy)args->packageNamingPolicy;
	if (IsRunningOnDesktop) {
	var packageNamingPolicy = Environment.GetEnvironmentVariable ("__XA_PACKAGE_NAMING_POLICY__");
	if (Enum.TryParse (packageNamingPolicy, out PackageNamingPolicy pnp)) {
	JavaNativeTypeManager.PackageNamingPolicy = pnp;
	}
	}
	SetSynchronizationContext ();
	}

Steps to Reproduce

Did you find any workaround?

No response

Relevant log output

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