audiopolicy: Fixed bug for rule file of strategy sonification respectful

If 'USE_CONFIGURABLE_AUDIO_POLICY' enabled, 'engineconfigurable'
will be used for devices selection. A bug was found in rule file
for strategy_sonification_respectful if rule file used to generate
PolicyConfigurableDomains.xml, and in that case the function of
AudioPolicyManager::getDevicesForStream will always return wrong
devices after device2, e.g., headset, connected and removed.

After removed, device2 should be reset to 'none', otherwise the
devices returned for strategy_sonification_respecful will always
not changed.

Change-Id: I656781ed46b73c5bef1f18612700a5547ea0043f