Add sysfs support

sysfs will turn on torch way faster than camera app.
As it isn't supported on all devices we keep using camera by default.
The developer that want to make use of sysfs should make an overlay to edit the path (if necessary) and enable it, like I did here: https://github.com/t4n017/android_device_samsung_janice/commit/9c671ba9a05460e137ed265d9ec1667d3aaabdf7

Change-Id: I0f7c5989e50871680d141dca150a2722b167ca9e
Automatic Translation Import

Change-Id: I46e87f8dd4aeb05d327f80075449ab3804fcd690
Automatic Translation Import

Change-Id: I6a9d31c98c5b9aa156ba36ba57554d991e1a7b2e
Automatic Translation Import

Change-Id: I9b29c9134aa5ed706d16c51135acbb51322ba0ba
Automatic Translation Import

Change-Id: I1f9ae26a8937ad5155b51df604f8d52f5e4bcee6
Merge remote-tracking branch 'origin/kitkat' into legacy

Conflicts:
	res/values-fr/strings.xml

Change-Id: I1cb2f90efc0a895287377f1ba3883ab554546fdd