Add feature declarations for a VR mode.

<?xml version="1.0" encoding="utf-8"?>

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<!-- This is the set of features required for a VR-compatible device -->

<permissions>

    <feature name="android.software.vr.mode" />

</permissions>

    <!-- Feature to specify if the device support managed users. -->

    <feature name="android.software.managed_users" />

    <!-- Feature to specify if the device supports a VR mode. -->

    <feature name="android.software.vr.mode" />

    <!-- devices with GPS must include android.hardware.location.gps.xml -->

    <!-- devices with an autofocus camera and/or flash must include either

         android.hardware.camera.autofocus.xml or