InCallUI: add decline and answer  incoming call action on notifications

Add decline and answer call action on notification if an call is incoming. Especially
usefull for call in background feature to have the ability to directly
decline or answer a incoming call. But as well usefull to decline/answer a second call
during one is incoming

PS:
- found a better way for the answer button

PS:
- fix keep flip action alive
- fix collapse notification shade when answering call
- answer call before starting the UI

PS:
- fix wrong user on sending close system dialogs

Change-Id: Ic958d1c1606b87c0024b791af5e094776c73748c
InCallUI: Set Ticker to contact

Display contact/number/confrence
	in notification ticker

PS2:
Implement Kufikugel's suggestion
	Incoming call ticker only

Change-Id: I4467c1d317160cfef211183e3cddc767dfb2e10a