Set AppOps settle time to zero when testing mid-stream blocking.

The delay AppOps uses when an app enters the background can lead to
slight flake on physical devices for these tests. Set it to zero to
reduce the chance of flake.

Bug: 377757612
Test: Ran 100 iterations of CameraPermissionTest, did not observe flake
Flag: EXEMPT not testing a new feature
Change-Id: I8222ece15f2d1fca2830d5069e64c29ffdc2178c