hwui: Fix a sporadic crash seen during CTS runs

 * It's possible (due to race conditions) that a patch might be
   scheduled for removal twice. Just print a warning and continue
   instead of asserting and crashing.

Change-Id: I42865f6717816a743cc49ba15b839e6c3b57ed83
[NEW WAY] Calculate position of center clock to not overlap with icons

- Based in this commit: https://github.com/CyanogenMod/android_frameworks_base/commit/36672e70e1d28d54c584f5e5ec978392381d0027

Change-Id: I6d3842111c18e371c18f694bc73c378212140782
Merge remote-tracking branch 'upstream/cm-11.0' into cm-11.0