wifi: Add is24GHzBandSupported API

The device may not support 2.4GHz, the framework already support to
generate default bsed which base on band supported or not.

Add is24GHzBandSupported to indicate App device support the 2.4G or not.
(The current user is CTS)

Bug: 175333688
CTS-Coverage-Bug: 179557841
Test: atest -c FrameworksWifiTests
Test: atest -c FrameworksWifiApiTests
Change-Id: Iecae57cab220c61340539fc8f0041dba753e0254
7 files changed