advanced reboot: add soft reboot option

Adds a "Soft reboot" option which restarts zygote, as requested in JIRA
CYAN-3998

Change-Id: Ia6e5ed9b053e1c5ebd1fc55e5692858b97f7e0fc
Signed-off-by: Roman Birg <roman@cyngn.com>
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_frameworks_base into android-4.4