Remove non intrusive incall ui (3/3)

There are several reasons for it

- to call every time a complete new activity is the wrong way. It needs
to be handled like google is doing it which keeps the activity permanent
alive to get it as fast as possible to the front. Especially noticeable on
slower phones

- of course current way freezes the forground app....so question what is
non intrusive on this feature

- Handling what happens when screen if off and the user is not in an
activity needs to be reworked

Whatever currently we have not much time to work that all out. So for
now we remove till this feature is completly redone. All points are solvable
but need work especially point 2 which is the most work. Other points are easy
to solve. Aside that our old feature "call in background"
returns back.

Change-Id: I629b749927d154cd36438b71c4a3552a7d6e3bf6
InCallUI: Incoming Call in Background (1/3)

Patch ported from 4.2 which was done by our lovely HCP. A
very popular one so we bring it back and adapt it to 4.4

Allows user to set that Incoming Call UI will remain in background
if screen is on. Instead, a notification is added to StatusBar, which
can be used to bring up the Incoming Call UI. Ringtone and vibration
still occur as per system settings.

This has the same effect as apps marked as "immersive". It prevents
the incoming call from backgrounding the current activity.

PatchSet:
- show normal inCallUI if keyguard is currently active

PS:
- cleanup

PS
- do not try to get the services if the feature is disabled

PS:
- do not disable notificationshade and navbar if it is a background call

PS:
- derp

Change-Id: I68e432a548c10d07cc9d668782cb544fbb4d421d
InCallActivity: consume back key on incoming call screen

Users will not be able to anything if the physical back key is
pressed on the incoming call screen (return to home screen with
nothing responding.)

Forward porting the key consumption from 4.3

Change-Id: Iea0734852bac7ca5a25e19ec9d9ee7c80dba6741
[3/3] Flip to Mute/Reject Call

Ported over from 4.2 implementation (thanks sasikumardr for that)

Original author of this patch was bugadani

We did just a cleanup

Provide easy mute and dismiss functionality for the phone application.

Available actions:

0: mute ringer
1: dismiss call
2: no action (default)

PS:
- fix NPE

Change-Id: Ia10df0045e9919c6b7efc97857abaeba246c365d