Add NetworkType alternatives to IMS APIs

Some IMS APIs were using ServiceState instead of
TelephonyManager.NETWORK_TYPE_* constants.

This CL cleans this API surface up.

Bug: 147726372
Test: atest CtsTelephonyTestCases; atest FrameworksTelephonyTests
Merged-In: Ic00b83f2d0d8950855d43edc49ad24ce577943af
Change-Id: Ic00b83f2d0d8950855d43edc49ad24ce577943af