Remove the usage of NoBandChannelHelper

NoBandChannelHelper is used on devices where HAL based
getChannelsForBand() APIs are not supported.

While getChannelsForBand() APIs are based on wificond now, we
can remove NoBandChannelHelper to reduce the code complexity.

This also fixes WificondPnoScannerTest, where both
createDummyScanSettings() and createDummyScanResults() should
be consistent on boolean |allChannelsScanned|.

Bug: 35707768
Test: compile, unit tests

Change-Id: I1c3007d6bb159c1b58c4b5370f8682fbeb8750d8
7 files changed