Wifi: omit PMK cache for WPA PSK networks

PMK caching has a security vulnerability for WPA/WPA2-PSK networks and
hence we should disable PMK caching for WPA/WPA2-PSK networks.

Bug: 152931766
Test: atest FrameworksWifiTests
Change-Id: Ic84a3413b573baf6176bcea8ea7ae22068a54d8b
3 files changed