audio: fix missing package name in attribution source

The attribution source passed by OpenSL ES does not have a package name
which is needed to register for app ops changes.
This CL moves the attribution source verification before we call
AudioPolicyManager getInputForAttr so that the package name is correct
when registering for app ops.
This CL also:
- limits the attribution check to filling missing package name
- adds system server in trusted source for client UIDs.
- removes redundant UID check in AudioPolicyService getOutputForAttr and
getInputForAttr as those are only called from AudioFlinger after verification
- Add missing attribution source verification in openMmapStream()

Bug: 243376549
Bug: 258021433
Test: verify app ops work with WhatsApp
Test: audio capture regression
Change-Id: I40040b8ace382f145dcfc8d04d81dcf6a259dfeb
Merged-In: I40040b8ace382f145dcfc8d04d81dcf6a259dfeb