Migrate Permission APIs to BinderResult

Migrate to return Results with error type binder::Status instead of
status_t for more descriptive failure messages and caller ease of use.

Refactor tests to support the new API shape and migrate to use newly
added unwrapping gtest matchers and BinderStatusMatcher.

Test: atest audiopermissioncontroller_test
Bug: 338089555
Flag: com.android.media.audio.audioserver_permissions
Change-Id: I0d05bbfdd6a2eb545dedb3d2ed0df7aa12fb21b2