Change Android platform for when ANGLE is default

Allow adb commands to select ANGLE vs the legacy GLES driver
regardless of which driver is the system (default) driver, and to
select between different versions of ANGLE if multiple versions are
installed (e.g. the built-in system driver vs. an updated APK).

Test: logcat
Bug: 224558229

Change-Id: I83e59002b67181fda4da6070b80ffa595bc25ac4