QCamera2: Don't initialize preview channel in ready state

 Flash torch configuration shouldn't trigger
 preview channel initialization/release once
 we are in preview ready state. At this point
 the client has already called 'startPreview'
 and the flash configuration will get applied
 once a valid preview window starts preview.

Change-Id: Ib44af3af593daabc7f1b901cd0b74eee773d20ad
3 files changed