Non-functional Oculus Quest focus awareness option

[m4gr3d]

Godot version:
3.2.2.stable

OS/device including version:
Oculus Quest

Issue description:
The Xr Features/Focus Awareness option is non-functional. Enabling the option does not add focus awareness support to the app.
This is caused by the fact that the manifest update logic adds a String value to the focus awareness meta-data instead of a boolean value.

Steps to reproduce:

• Enable the Xr Features/Focus Awareness option
• Run the app on an Oculus Quest using the Godot Oculus mobile plugin.
• Press the Oculus Home button on the right touch controller
  When focus awareness is enabled, the Oculus universal menu should show within the running app. Instead the user is taken outside of the app to the Oculus Home environment.

Minimal reproduction project:
https://github.com/GodotVR/godot_oculus_mobile/tree/master/demo

[m4gr3d]

The workaround for Godot v3.2.2 is to manually edit the res://android/build/AndroidManifest.xml file and replace oculus_focus_aware_value in <meta-data android:name="com.oculus.vr.focusaware" android:value="oculus_focus_aware_value" /> to the desired option (either true or false).