Cleanup RadioOnHelper and supporting methods

Minor changes to comments and fixs possible bug
introduced in refactor: The phone type should
be saved before the radio is turned on in order
for the TelephonyConnectionService to switch
the phone type later if it changes when the
call is placed.

Test: Telephony Unit Tests
Merged-In: Id6c1c3299bacbb4335cb5bf62f76de7a7b90a298
Change-Id: Id6c1c3299bacbb4335cb5bf62f76de7a7b90a298
5 files changed