Camera2: Auto exposure correction has no effect on final image

[simonschmeisser]

But works in viewfinder mode

[b100dian]

I am noticing a nuance here: the exposure compensation does work.
However, the next shot, even if it shows the same +/- compensation in the UI, is ignored in the viewfinder and in the picture.

But this is not the only setting ignored at startup, I found that even other settings such as edge mode and noise reduction quirks as I tried to implement them in this draft PR are not taken into account at startup.

But they are taken into accoun if you change.. exposure compensation for the current shot.

So, in the end, this looks like a race between initializing the camera/viewfinder and applying these settings (which includes exposure compensation but also more)

[b100dian]

I made a hack around this, but not the true solution - I find it hard to follow gst-droid in this regard: #122