Traffic meter: show summary of traffic in brackets

Change-Id: I00b056bc0076fdc9e3d573dfe4b0fb7c7aa11e0a
Traffic meter: Selectable summary timeout [1/2]

Change-Id: Ib3465fa2c719822d09cd7ba107a047c889b4a93f

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/policy/Traffic.java