RingtonePlayer: preventative cleanup before a SecurityException

Before throwing a SecurityException, also stop any client trying
to access a URI they don't have access to.
This has also the intended side effect of removing that Client
instance from the mClients HashMap.

Bug: 406744501
Bug: 400434060
Test: atest com.android.systemui.ringtone.RingtonePlayerTest
Flag: android.media.audio.ringtone_user_uri_check
Change-Id: If338948c915e808f8ae0d7dc0ddd4cabaf329a7c