Make SignalStrength constructor system APIs so that it can be accessed by TelephonyRegistry Bug: 140908357 Test: make Change-Id: I80693b0f1b1f9de1a8c93ce8a23a816346afb634
Make SignalStrength constructor system APIs so that it can be accessed by TelephonyRegistry Bug: 140908357 Test: make Change-Id: I80693b0f1b1f9de1a8c93ce8a23a816346afb634