Peek wake timeout (1/2)

- Originaly taken from AICP - Thath's why i'm keeping original autorship
- Allow user to set how long peek notification will hold screen on
- Minor changes by me @cristianomatos to match crDroid sources

Diff from original commit:
* Variable declared globaly and moved from inside the private void scheduleTasks() method
* Made multi user

Original commit: https://github.com/AICP/frameworks_base/commit/90b47fc55ec59520d6dd5dd828ff48a3a3dca1d4

Change-Id: I3a3c7e6f99edd9c861566b2d738d31e7657a0322