Use context AttributionSource as the identity source-of-truth for connection

CameraService::connect and ::connectDevice allow an argument of USE_CALLING_*
for both the pid and uid of the client. In this change, USE_CALLING_* is
retired in favor of using the AttributionSource provided by the calling
Context. The AttributionSource pid/uid is verified to be truthful via
getCallingPid() / getCallingUid().

This change has no impact on APIs which do not pass the pid/uid through
ICameraService - the AttributionSource pid/uid are ignored for those
APIs and the calling pid / uid are still universally used.

Bug: 190657833
Bug: 369850244
Change-Id: I622c24b7ace926645b64ac70650e401dc7ad5f1e
Flag: com.android.internal.camera.flags.use_context_attribution_source
Test: Ran new CTS test with flag on/off