GlobalActions: Add null checks to onServiceStateChanged

can potentially cause a fatal NPE.

Signed-off-by: bmc08gt <bmc08gt.teamb00sted@gmail.com>
Change-Id: I7943c2db663157296cf69e524a15fd71bf017496
SystemUI: Reboot Toggle

onClick: 3-way Reboot Menu
onLongClick: Screen off then reboot

ToDo: Allow invert of onClick<->onLongClick

Signed-off-by: bmc08gt <bmc08gt.teamb00sted@gmail.com>
Change-Id: Ibc601112ede88490c1dd6e5d01122e5037244150