Add hidden APIs for retrieving LTE RSRQ and RSSNR

Change-Id: Iff3c4869830321b979cf0c2c6a9076efda943389

telephony/java/android/telephony/CellSignalStrengthLte.java

@@ -167,6 +167,20 @@ public final class CellSignalStrengthLte extends CellSignalStrength implements P
         return level;
     }
 
+    /**
+     * @hide
+     */
+    public int getRsrq() {
+        return mRsrq;
+    }
+
+    /**
+     * @hide
+     */
+    public int getRssnr() {
+        return mRssnr;
+    }
+
     /**
      * Get signal strength as dBm
      */