Support more `os` under Ravenwood.

Tests for these internal utils are local within the frameworks/base/
repo, instead of in CTS.

To help future-proof, bring the entire os/* test directory by
default into the Ravenwood suites, and give developers the way to
easily opt-out with @IgnoreUnderRavenwood at the class level.

Bug: 292141694
Test: atest FrameworksCoreTestsRavenwood FrameworksCoreTests
Change-Id: Ia3c72c22fb3ebc8cfec7a4f9811b7e27a783e885