vc: Use oportunistic connect mode

With this patch, VC uses opportinistic connect
This is needed to proper handle reconnection and switch between BR/EDR
and LE

Bug: 282778469
Bug: 279990836
Test: atest bluetooth_vc_test
Test: atest BluetoothInstrumentationTests
Tag: #feature

Change-Id: I9e881d6c26cada4c4b49bbe8558a659a1af559df