Dialer app changes for IMS

IMS Conference URI UI changes
1. Add a new button for initiating conference
URI call in the Dial screen.

CRs-Fixed: 681851

Conflicts:
res/values/strings.xml
Change-Id: If78c82bec2d583f9012ea2e824589a6099f76a94
Fix to remove unwanted string in Dialer

Set the visibility of recipients view  to gone

Change-Id: I5f7268b4282f4984a481371476eb6d41d3073dfb
CRs-Fixed: 724363
PhoneCommon: Set ringtone for SIM2 using SUB ID.

Add support to set ring tone for SIM2.

Change-Id: Ibeb26c16a90eb2273f5bf58826e47d2e9d939d6d
STK Call Control feature implementation.

Support to display the exact call failure reason
for STK cc.

Change-Id: I50796fc3df6c0153aa2fe65f0e86b506f996e039