Camera ITS: Update test_auto_flash.

Updated test_auto_flash to follow precapture sequence and capturing
single image with ON_AUTO_FLASH in single capture session.
Currently we are testing jpeg format and will be updated to test yuv
format along with different aspect ratios in next release.
Added a check to make sure that the flash turns off after it was fired
during still capture.

Bug: 222126851
Bug: 200591976
Test: Tested on Pixel device.

Change-Id: I09031cfd56306fbbcb9a6b455e0df61ebe9e3da9
3 files changed