Add the permission for shell to test CtsVoiceInteractionTestCases

To test the AlwaysOnHotwordDetector behavior in battery saver mode,
we need the permission SOUND_TRIGGER_RUN_IN_BATTERY_SAVER.

Bug: 271511359
Test: atest AlwaysOnHotwordDetectorTest
Change-Id: I62c6fd21b58beddb1733f7e8e1bbf91b0b602b83