wifi: Add WifiMananger API is60GHzBandSupported

New system API mostly for usage from Settings,
to update the UI with features such as 60GHz band
selection in case the device is configured with 60GHz
support.

Bug: 147469373
Test: Manual - enable wifi and connect to an access point
Test: atest FrameworksWifiTests
Test: atest FrameworksWifiApiTests
Change-Id: Idb6b5350aaf1566df6a39fc0e3432f8464bf6df1