Refactor EmergencyCallHelper to better handle DSDS

Refactor EmergencyCallHelper to better handle DSDS radios by disabling
airplane mode and waiting for each Phone's ServiceState to change to
allow for Emergency Calling.

Also, some tests are added using AndroidJUnit4Runner

This is the first part in a series of changes to the Telephony code.

Bug: 28200728
Change-Id: I642615480090f0b047cea00ab9f3256f321dfaa1
9 files changed