Add set-time and set-timezone shell cmds to alarm service

These commands allow a user to set the time and the timezone
from the shell. The shell now has signature|privileged
SET_TIME and SET_TIME_ZONE permissions.

Bug: 67751701
Test: manual - correctly sets the time and timezone from unrooted adb.
Change-Id: I1d2820fd7dadd8b1f3900c0592eb28210370ce88