GraphicsEnvironment: Expose query to determine ANGLE use

Move the early logic that decides whether ANGLE should be used
to a static public function that can be queried elsewhere
without setting up the environment further.

Bug: 130029351
Test: atest CtsAngleIntegrationHostTestCases

Change-Id: I908233d46631ec91dca714bff3f8fd9341160c9e
2 files changed