[Cherry-pick] Add debug property to safe guard ANGLE developer option UI. am: 3182b0e298

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Settings/+/2794055

Change-Id: Ib6b009eeead559c0299d4f76dd927c5a5fc87d20
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>