Add a circlular memory indicator to the "clear all" button area in recents panel.

PS2: Have the CircleMemoryMeter update every 100 milliseconds and be fully self contained so no need to call update from elsewhere.

PS3: Add 2dp padding to the top and right of the meter.

PS4: Clean up formatting.

Change-Id: I315d8bf0f566415f93444ed17891c585d79c9bca
Merge "Add a circlular memory indicator to the "clear all" button area in recents panel." into jellybean-mr1