Add network latency to performance overlay

app/src/main/java/com/limelight/nvstream/jni/MoonBridge.java

@@ -306,5 +306,8 @@ public class MoonBridge {
 
     public static native String stringifyPortFlags(int portFlags, String separator);
 
+    // The RTT is in the top 32 bits, and the RTT variance is in the bottom 32 bits
+    public static native long getEstimatedRttInfo();
+
     public static native void init();
 }