Bug 857896 - Convert device property "Connected" into a boolean if bluez returns a two-byte array. r=echou, r=qdot, a=tef+
Bug 875719 - Simplify and correct the mechanism of handling call state change event. r=gyeh, a=tef+

1. Remove variable mCurrentCallIndex and replace with using function FindFirstCall(aState)
2. Remove unused variable index and callArrayLength