Update call extras with call composer data.

To initiate call composer based call we need
to populate call extras of the call intent with
key-value pairs that holds call composer data.
Since we currently don't have Call Composer specific UI,
Settings.Global is used to retrieve call composer data
and pack it into the bundle of the call intent.

Change-Id: Iba0e5137681c9c67fd0ec26f4aeaea4faaf77d66
CRs-Fixed: 2643693
3 files changed