Remove FG state check from UCE APIs

Upon API review it was determined that FG state check
of UCE APIs would not be necessary. Removing...

Bug: 182198113
Test: atest CtsTelehponyTestCases:RcsUceAdapterTest
Change-Id: I29a9b62d554429c2f253d19e47799d1aebb3e9b9
Merged-In: I29a9b62d554429c2f253d19e47799d1aebb3e9b9