Base: On-The-Go: Allow to toggle between front and back camera

Video Preview:
https://www.youtube.com/watch?v=MnPGn0zwpEw

In case you want to pick that feature, feel free to edit the
commit message to get rid of that ugly video ;)

Change-Id: Ia6422bf5bbd531240e62ee57de316a8e6f94546c
Base: On-The-Go: Several fixes

handle camera in surfacetexture
check if notification manager is null before canceling
restart timeout when changing the camera mode
convert settings observer to a local variable
remove redundant try-catch clauses

Change-Id: If637e30f69706dc8b3f1397fafacb24c7bbb5083
Base: On-The-Go: Overlay status- and navigation bar as well

Change-Id: I067981028340cdd53fe112cae9b7a4ddcb7532a8
Base: On-The-Go: Change the way of changing the camera mode

changing it on the fly is too buggy like i have done it.
sometimes things fail and we are getting stuck ;P

on mode change, save the value, create a notification and stop the service.
the notification allows to restart the service.

Change-Id: Ie02f01a4ab2f856cd58fe5fde8c49220bf7efd4b
Base: On-The-Go: Switch Licenses to GPLv3

Change-Id: I3906fd0684b91e6e0535c5b9c5623fcf535e1eb3
Fix build