Flipping NR signal strengths coming from HAL

The documentation of NrSignalStrength states that some
of the cell signal strength values should be flipped when
taken in from the HAL (this matches what LTE does.)  The
current implementation did not match this behavior, this
chagne fixes that.

Bug: 144667130
Test: FrameworkTests
Change-Id: Ica2595c5b6480a52209fe5ec93de63c9f323316a
Merged-In: Ica2595c5b6480a52209fe5ec93de63c9f323316a

telephony/java/android/telephony/CellSignalStrengthNr.java

@@ -155,7 +155,17 @@ public final class CellSignalStrengthNr extends CellSignalStrength implements Pa
      * @param ss signal strength from modem.
      */
     public CellSignalStrengthNr(android.hardware.radio.V1_4.NrSignalStrength ss) {
-        this(ss.csiRsrp, ss.csiRsrq, ss.csiSinr, ss.ssRsrp, ss.ssRsrq, ss.ssSinr);
+        this(flip(ss.csiRsrp), flip(ss.csiRsrq), ss.csiSinr, flip(ss.ssRsrp), flip(ss.ssRsrq),
+                ss.ssSinr);
+    }
+
+    /**
+     * Flip sign cell strength value when taking in the value from hal
+     * @param val cell strength value
+     * @return flipped value
+     */
+    private static int flip(int val) {
+        return val != CellInfo.UNAVAILABLE ? -val : val;
     }
 
     /**