CameraProxy: Clear calling identity before scheduling

Camera statistics job scheduling cannot be triggered by
native camera service UID. Clear the binder calling
identity before trying to schedule any jobs.
In addition to that check also the binder calling UID value
itself and make sure we are being called by camera service.

Bug: 77818243
Test: Camera CTS
Change-Id: I5d94671eaf0eb41b5d06abf10494b9e7dc172db5