Add temp ANGLE rules support

If root is available or the app is debuggable,
check for the following property and use it to load
a rules file instead of the one that comes with ANGLE:

  debug.angle.rules

For example:

  adb shell setprop debug.angle.rules /data/local/tmp/a4a_rules.json

Bug: 80239516
Test: Manual build, ensure rules behave as expected
Test: cts-tradefed run singleCommand cts -m CtsAngleIntegrationHostTestCases
Change-Id: Ie43c67c078ad962ba12f1046a878f79216660755