Heads up: Launch in floating window

Add some part of NotificationHelper
Credits to AOSPA team

Change-Id: I7001cebd69790b46b8dcfe9150c7ef104e5427a2
Heads up: Fix notification disappearing too quickly with expanded desktop on

Change-Id: Icd6eada35ebaf33c426e9c98fdf4e502b99b2e9b
Heads up: Add blacklist feature (1/2)

Credits to AOSPA Team

Change-Id: I976587d779319116a65f2f0851481b3db6d11821