NetStats: Add net stats to system bar.

PS2:
PS3:
Hide net stats view when notification area is disabled.

AICP:
PS2: Fix build by adding a missing networks_stats id

Change-Id: Ib35dd46b026dab00abe73966105806c54266e466
Fix double clock on tabletUI when center clock is enabled

Change-Id: I27c1e24746e74c9780ede35a2979b4181ebeffb0
Merge changes I27c1e247,Ib35dd46b into jb-mr2

* changes:
  Fix double clock on tabletUI when center clock is enabled
  NetStats: Add net stats to system bar.