Don't return false if the Phone is GSM for ECBM

ECBM can still be triggered on CDMA+LTE voice
RATs when there is no SIM and the phone camps
on a CDMA+LTE network. We should still be able
to get into ECBM in these cases.

This change removes the GSM only check for
isInEcm().

Bug: 62042256
Test: Build and run
Merged-In: I4f023339968631d2a34146f9ff1f5b4a58e1e656
Change-Id: I4f023339968631d2a34146f9ff1f5b4a58e1e656