InCallUI: add Incoming Call Background (non-Intrusive InCall improvement)

last week, as we know we have bug with non-Intrusive Incall on Back pressed
and we already fix that by disabled Back pressed while non-Intrusive InCall enabled

instead disabled Back pressed, this patch introduce non-Intrusive Incall will go to background mode
using Notification on Statusbar

Based on SlimRoms patch
https://gerrit.slimroms.net/1857

with changes to follow Intrusive Incall

ps5 - allow flip actions while call is in statusbar/notification area (background)
    - show the navbar so devices without hardware keys can actually have the back
      button there

Change-Id: Id9456a48fc767a7a3fe46912c7cba0d3dee93991
InCallUI: fix non-intrusive for RTL

http://jira.omnirom.org/browse/OMNI-522

Change-Id: Ib712ccc2c207e329bdfa4cf64d29f2aeb130f59b
InCallUI: non intrusive incall ui rework

Use glow pad with accept and reject target
Added button to open fullscreen ui

PS8:
-simple flat style again

PS9: added some bells and whistles
-added hide animation
-added background button
-added swipe down to background

PS10;
-added button pressed feedback

Change-Id: I12ea058ed970b13608c5abfa8c0cd535dfc621ae
InCallUI: non intrusive incall ui: fix glow pad layout

Change-Id: I8350e59ee7fba6e8ec2e0a06f3617060c5c204f0