Bluetooth: Set isPreferred to true for PanProfile Connections.

isPreferred is always true for PAN profile so that DUT can
initiate connection with remote device. Curretnly we are
returning true only when pan profile is in connected, so
it will return false when pan profile is not connected and
will never initiate connection on click.

Change-Id: I7c789add73ca944d074b0ecd8af223f6d61b547a
CRs-fixed: 463887