wifi: Dynamic country code update when Soft AP enabled

The country code change will cause supported channel list change, and
it rely on wificond to handle that, add init wificond interface when
SoftAp enabled.

To enable this feature, it requires to configure feature in overlay
configuration.

Bug: 173000706
Test: atest -c FrameworksWifiTests
Test: Manual Test on Pixel 4a, country code can be passd to SoftApManager
correctly and supported channel can be updated after country code
changed when SAP enabled.

Change-Id: I419295bb973792c667b8769163d8ab4a0b4208b0
11 files changed