InCallUI: customize video call UI

Include following customization for video call UI:

1. Prevent make video call for some carrier:
To meet some regional carriers requirement, check if phone number
less than 7 or contains #, * or non-digit characters before making
a video call.

2. UI enhancement for IncallUI of video call:
Add UIs for answer_rx, answer_tx, answer_video, decline_video to make
the UI more friendly to end user.

Change-Id: I310bcbf021f1217a6e2a648d33b266297d7d9212
CRs-Fixed: 1039326