Improve the check for SIM presence.

Earlier it was done based on SubscriptionsChangedListener which
timing wise is not a very appropriate trigger, particularly since
it can clear some values cached from the current SIM. Now the
check is based on querying SIM state.

Test: manual
Bug: 112333424
Merged-in: I2b49baf98c5aa2924318b6dc2e353c79390a47e8
Change-Id: I2b49baf98c5aa2924318b6dc2e353c79390a47e8