The recent CL to remove the Settings GUI from the Android-built APK went
a little too far removing Java code and emptying the
AndroidManifest.xml. This resulted in ANGLE being unable to be loaded
from the APK, since ANGLE was not able to respond to the intent
android.app.action.ANGLE_FOR_ANDROID which indicates it contains ANGLE
libraries.

The AndroidManifest.xml requires various flags like
android:forceQueryable="true" so the APK can be accessed by the
framework.

The assets/ directory was removed, which contains 'a4a_rules.json' and
is required by GraphicsEnvironment. This is added back.

Bug: b/187342779
Change-Id: Ic7b758c92ed12750972c7e313729276a13f76032
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2906632Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Tim Van Patten <timvp@google.com>