wifi: allow manual connection to a Passpoint provided network

While connected to other WiFi network, a Passpoint AP with its
provider installed will shown as "<SSID> available via
<Provider Name>", since the installed provider contained
necessary credentials needed to connect to that AP.

This CL will trigger a connection to that AP when the user
taps on it for manual connection.

Bug: 36357280
Test: manual connecting to a Passpoint network while connected
      to other network

Change-Id: Idec440aa1606e80bcea56054e77ef2dc50a7ac93