Added isPhoneTypeCdma() and isPhoneTypeCdmaLte()

Also includes:
- Removed unnecessary unreg/reg of phone with CallManager on
voice radio tech change. This is needed as otherwise Ims Phone may
get unreg but not reg again (on radio tech change).
- Allowing reg/unreg in GsmCdmaPhone regardless of phone type
- Removed unused Call.mIsGeneric

Bug: 25793157
Change-Id: Ie2093a50c1cf64918782076127decff90968fe72