cameraserver: inherit RT priority for AIDL HAL ICameraDeviceCallback calls.

Bug: 242077173

Test: Check perfetto trace; When camera HAL has an RT thread making a binder call to cameraserver
      the serving threads priority is RT as well (bug has details)

Change-Id: I1f07176ccc07a8e523289a5d1e47c9cec66c765f
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>