advanced reboot: add soft reboot option

Adds a "Soft reboot" option which restarts zygote.

Also includes "ShutdownThread: set soft reboot trigger accordingly"
commit by Dan Pasanen <dan.pasanen@gmail.com>

Signed-off-by: Roman Birg <roman@cyngn.com>
Change-Id: Ia6e5ed9b053e1c5ebd1fc55e5692858b97f7e0fc
Revert "(1/2) Add support for using the flip switch (Samsung cover) to turn off the screen"

This reverts commit f9d6f17446fa56e176a1eb068ae3dca6af726eaf.

Change-Id: I82a5d5c82d004c2303a610be10a896c0d64de9d2
Merge "advanced reboot: add soft reboot option" into kitkat3