Make ANGLE by default built to system partition on Android Now that ANGLE on system is in fully released, clean up the build file configuration and remove the flags, but add an option to allow ANGLE to be built in vendor partition so that clients can continue using ANGLE on old OS versions. Bug: b/293503000 Test: atest CtsAngleIntegrationHostTestCases Change-Id: Ie53c2a92493bbab016bef967aacb10b3754aca57 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5333890 Commit-Queue: Peiyong Lin <lpy@google.com> Reviewed-by: Yuxin Hu <yuxinhu@google.com> Auto-Submit: Peiyong Lin <lpy@google.com> Reviewed-by: Cody Northrop <cnorthrop@google.com>