HOVER: Don't process and/or show foreground app notifications

- Don't show notification of foreground app
- Animate the ticker in this case so user can see it

Inspired from changes linked here https://gerrit.paranoidandroid.co/#/c/4453/10

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I9f45e1641a7478c7e460c32133db00bd67f63e75

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/notification/Hover.java