Add ServiceState#isUsingNonTerrestrialNetwork value to its toString().

Since being introduced in Android V the toString has not been modified
to reflect the new value apart of the ServiceState. This will aid in
debugging ServiceState going forward.

Test: manual
Bug: 356181166
Change-Id: Ie3f5470d9972a1f5f0e583fb14d0911a1f25d53b