Telephony: Keep RADIO state off in APM for iwlan RAT.

- Due to polling in APM the current service state gets changed
from OFF to OOS which is incorrect.
- Let the radio state be in OFF state and added additional checks
to allow non-default PDP activation if current RAT is iwlan.

Change-Id: I3f62b225fa2345a278858560a44ccd6ab1a9e32a