Remove unnecessary UWB functions

The removed functions provided no added benefit to the current UWB
API. For instance, the supported channels for an individual protocol
may be different than what UwbManager#getSupportedChannelsNumbers
would return. Instead, the supported channels are provided through the
UwbManager#getSpecificationInfo API which allows a client to easily
see which channels (and other parameters) a particular protocol
supports.

Bug: 180533171
Test: atest UwbManagerTests CtsUwbTestCases
Change-Id: I81675429d73486f0b002e76acabaa4883990ab11