IMS: Add isImsRegistered API in QtiImsExtManager

1)Add utility API to return the IMS Registration Status
for a particular phone ID.
2)Remove redundant API isConnected and isOpened.

Change-Id: I83077e35f4796fb7f63091b21d5add4faa62870d
CRs-Fixed: 2204129
1 file changed
tree: 3b7d89e37c1dcafc044de60c8cd18c1f360dc30c
  1. ims/
  2. internal/