[camera] camera integration test bit rate test fails #194395

1. Follow these steps to run integration test for camera plugin
2. Observe one of the test failure: this test.

Details: This test verifies higher bit rate having larger size. The test may pass or fail depending on how I put my iPhone on the table. More context: #191202 (comment)

We should also remove the equivalent tests from other platforms (e.g. the android equivalent tests currently just check size > 0), which isn't helpful.

Based on the commit history, Android used to do the same test as iOS, but later changed to size > 0 to pass the CI. Note that it still leaves for (var n = 0; i < lengths.length-1; n++) - the -1 bound only made sense when comparing length[n] against length[n+1].

On iOS, since we run on simulator on CI, so the test returned early on if (cameras.isEmpty) return;