Add support for Wifi calling settings UI [3/4]

-- Add support for below UI for wifi calling settings
   - Add configuration flags to control UI options
   - wifi calling setting - user can change wifi settings to ON/OFF
   - wifi calling preference - User can select wifi calling preference.

Change-Id: I139d40bae55a6db4b1db4f5e4a234b26eea5a4b5
CRs-Fixed: 818899

Conflicts:
	res/values/config.xml
	res/values/strings.xml
30 files changed