Add CAPTURE_AUDIO_OUTPUT permission requirement

Add the CAPTURE_AUDIO_OUTPUT permission requirement annotation to
setShouldScreenCallViaAudioProcessing -- this permission is needed to do
call screening once the call has been placed into the special state.

Fixes: 146563331
Test: atest BackgroundCallAudioTest
Change-Id: I8eec1e19c6512d54f39cd9ad63347a2ac0ec2a98