Wi-Fi network connection support for STA+STA with multiple internet.

Add the WifiNetworkFactory for MultiInternet.
Add the MultiInternetManager for managing the use case.
Add the unit tests for the MultiInternetManager and the
MultiInternetWifiNetworkFactory.

Bug: 181741503
Test: atest FrameworksWifiTests
Change-Id: I59a61c76fb4182762bb1b2a66dac92095daad5f9
16 files changed