Camera CTS: Fix cts testFlashTurnOff failed

For camera that does not have flash,
CTS currently requests flash requests even though
the camera does not support CONTROL_AE_MODE_ON_ALWAYS_FLASH, which
blocks camera platform to return buffer to camera service.
Therefore, Evaluating flash capability of the camera under test is
added on this commit.

Bug: 142217385
Test: CTS build and execution

Change-Id: I1a05e475004b2e28dc8a239a521e8e187f5d6ca9