Rework ChannelHelper classes

This commit is to rework ChannelHelperClasses for more optimized
handling of channel lists.
Current implementation does a lot of copying of channel spec arrays
in a non-scalable way with the addition of new frequency bands.
Accordingly as a prep work for support of 6GHz band, this commit
improves this behavior.

Bug: 139354972
Test: atest com.android.wifi.server
Change-Id: Idd737ba19dd482b281f7333f8b5534d72e650ff6
4 files changed
tree: ab44b19f07ae65c6388395a9b13f436567b17e9c
  1. apex/
  2. service/
  3. PREUPLOAD.cfg