Add CTS tests for clearing compat overrides on release builds

Those CTS tests verify that a package with the required permission can
successfully clear overrides on release builds as long as those compat
changes are marked as @Overridable.

Bug: 183183372
Test: atest CtsAppCompatHostTestCases
Change-Id: I0e9eba8b5b35aae910b9a6fa853a2c7f4946e1f4
2 files changed