AudioService: fix removeDeviceAsNonDefaultForStrategy regression

Calling AudioManager.removeDeviceAsNonDefaultForStrategy with
an invalid strategy is expected to fail (as documented).
Fix by returning a failure when the useCase (aka strategy) and
role is not found in the map of roles for the audio devices.

Bug: 280554476
Test: atest android.media.audio.cts.NonDefaultDeviceForStrategyTest#testInvalidStrategy
Change-Id: I29f9d9a5d9e7fb2c0865dfa0c86e7531bb148b41