Apps: Add blacklist interface [1/2]
Include peek and floating mode implementations.
Applies to every floating mode launch way.

@cristianomatos: Include Halo in new blacklist button and some code adjustment and clean-up related

Part of this commit is also included: https://github.com/AOSPA/android_frameworks_base/commit/5a2d73e519c001359c4cd139164633ff02ed8658

Change-Id: I8b5f63e1ea3e47d22c1780aa9d29a9e958fbe97e
Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Revert "Halo: allow choose notifications on floating window or not (1/2)"

This reverts commit 1840544384f7e32102373b3ecc80fd0320e3e89c.