SystemUI: bug fixes, cleanup, and maintenance

Change-Id: Ia1f3e851c9fc93f0cea705fa73162f048dab5c68
PS1: basestatusbar: make halo enabled more efficient and fix multi-user broadcast receiver
PS2: remove unused constants from a few classes
PS3: turn off gesture debugging in PhoneStatusBarView
PS4: remove unused classes from BaseStatusBar
PS5: add try/catch blocks for the date/time click actions in the notification shade