Simplify logic for getConnectionStatus in HidDeviceProfile

* getConnectionStatus: remove connected device check logic.
  HidDeviceService will check it.
* rewrite the annotation about this class
* remove member variable DEBUG and related checks.
* add robotest for HidDeviceProfile

Bug: 111812003
Test: make -j42 RunSettingsLibRoboTests ROBOTEST_FILTER=HidDeviceProfileTest
Change-Id: I2e7fdd69a46707339a32db4304666e50fd0cf954
Merged-In: I2e7fdd69a46707339a32db4304666e50fd0cf954