IMS-VT: Bring InCallUI to foreground using "Heads up" bar.

Android framework displays "Heads up" notification
bar with set of buttons that can be used to accept the
incoming call, when the screen is on.

Currently up to three actions (buttons) can be added to the
notification bar. Phone Application adds "Dismiss", "Voice"
and "Video" actions. Since there is a limit (3) on the number
of allowed acions, adding "VideoTx" and "VideoRx" actions to
the notification bar without increasing the current limit is
impossible. Changing the max allowed actions will invalidate
public and published API and corresponding document.

This change replaces "Video" with "More" action which will
bring the phone application to foreground and show the standard
incoming call UI.

Change-Id: I94c21cca42d378fba6dccf2225313177d9da2411
CRs-Fixed: 753053