Fix issue 2712130: Sholes: problem when playing audio while recording over bluetooth SCO.

The problem is that when an input stream is opened for record over bluetooth SCO, the kernel
mono audio device should be opened in RW mode to allow further use of this same device by an output stream
also routed to bluetooth SCO.
This does not happen because of a bug in AudioSystem::isBluetoothScoDevice() that does not return true
when the device is DEVICE_IN_BLUETOOTH_SCO_HEADSET (input device for blurtooth SCO).

Change-Id: I9100e972931d8142295c7d64ec06e31304407586