Create emergency account with primary stack phone.

When creating emergency account associate the primary
stack phone with it as emergency calls will be placed
only on primary stack with no sim cards on the device.

Change-Id: I63a9d54950330991e7a93ec8c3982a70d4cdd741
CRs-Fixed: 965269

Author: Ravindra

telephony/java/com/android/internal/telephony/IExtTelephony.aidl

@@ -161,4 +161,11 @@ interface IExtTelephony {
     */
     int getUiccApplicationState(int slotId, int appIndex);
 
+    /**
+    * Get primary stack phone id.
+    * @param - void
+    * @return phone id
+    */
+    int getPrimaryStackPhoneId();
+
 }