Include marshal-ilgen Mono component by default

Context: dotnet/runtime#71203
Fixes: #7249

Apps on this PR currently crash with:

    mono-rt : [ERROR] FATAL UNHANDLED EXCEPTION: System.InvalidProgramException: Invalid IL code in (wrapper managed-to-native) object:wrapper_native_0x7725af156f10 (intptr): IL_0012: calli     0x00000003
    mono-rt :    at System.Runtime.InteropServices.Marshal.PtrToStructureHelper(IntPtr , Object , Boolean )
    mono-rt :    at System.Runtime.InteropServices.Marshal.PtrToStructure(IntPtr , Type )
    mono-rt :    at Java.Interop.JniRuntime.CreateInvoker(IntPtr )
    mono-rt :    at Java.Interop.JniRuntime..ctor(CreationOptions )
    mono-rt :    at Android.Runtime.AndroidRuntime..ctor(IntPtr , IntPtr , Boolean , IntPtr , IntPtr , Boolean )
    mono-rt :    at Android.Runtime.JNIEnv.Initialize(JnienvInitializeArgs* )

Which, I assume is due to a missing Mono component.

We should add the component by default:

    <_MonoComponent Condition=" '$(_IncludeMarshalIlGen)' != 'false' " Include="marshal-ilgen" />

In the future, someone could experiment by setting
`$(_IncludeMarshalIlGen)` to `false`.

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.AssemblyResolution.targets

@@ -198,6 +198,7 @@ _ResolveAssemblies MSBuild target.
       <_MonoComponent Condition=" '$(AndroidEnableProfiler)' == 'true' " Include="diagnostics_tracing" />
       <_MonoComponent Condition=" '$(AndroidUseInterpreter)' == 'true' " Include="hot_reload" />
       <_MonoComponent Condition=" '$(AndroidIncludeDebugSymbols)' == 'true' " Include="debugger" />
+      <_MonoComponent Condition=" '$(_IncludeMarshalIlGen)' != 'false' " Include="marshal-ilgen" />
     </ItemGroup>
     <ProcessNativeLibraries
         InputLibraries="@(_ResolvedNativeLibraries)"