clang-format always manages to mix spaces into tab-based indentation.
Since we already require an exact tab-width of 8 it makes more sense to
use spaces.
makes trigger focus, continuous focus, autogain, gain ctrl, auto
exposure, exposure ctrl run in background to not block the UI thread.
The camera updates the image while this is in progress, so you can for
example see the camera live focus as on common other phones.