isStateUnknown() shall return true if the SIM state is still unknown

It is possible that the new card state 'PRESENT' is notified but new ICC
state is not notified yet. 'UNKNOWN' is the appropriate state in that
scenario.

Bug: 122091742
Test: Manual test

Change-Id: I6d812bb41023270cb6e78b028e426f82b62208a0