No feedback when attempting to transfer to an unpowered BT device

-Set transfering state when trying to connect
-Reset to onTransferBluetoothDevice when failing connecting
-Add test cases

Bug: 152606143
Test: make -j50 RunSettingsLibRoboTests
Change-Id: Ifc4cb16a5d7d2b2c85b1171aa070651a5feaa4e2