Opt out test using hidden API from Ravenwood

The test is using a hidden API, ResourceManager#getDisplayMetrics, to
test the behavior consistency. It will always return a zero value under
ravenwood environment without an override.

The test doesn't fail on real device environment nor cuttlefish
environment.

Test: atest FrameworksCoreTestsRavenwood
Test: atest FrameworksCoreTests#ResourcesManagerTest
Bug: 371502572
Change-Id: Ief8593ab62a46260178df9ec362166bc5c6dc942