Halo: Modify behavior

Don't ping when halo got "silent" notifications.

Also delay 10 sec before initializing Halo
or it'll never ping when receiving any notifications.
I don't know why this bug occurs.

Change-Id: I54d16d8aefbf173e6edcdf4f2fc3e6cbf6f55420

Conflicts:

	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/halo/Halo.java