Add network latency to performance overlay

app/src/main/res/values/strings.xml

@@ -110,6 +110,7 @@
     <string name="perf_overlay_incomingfps">Incoming frame rate from network: %1$.2f FPS</string>
     <string name="perf_overlay_renderingfps">Rendering frame rate: %1$.2f FPS</string>
     <string name="perf_overlay_netdrops">Frames dropped by your network connection: %1$.2f%%</string>
+    <string name="perf_overlay_netlatency">Average network latency: %1$d ms (variance: %2$d ms)</string>
     <string name="perf_overlay_recvtime">Average receive time: %1$.2f ms</string>
     <string name="perf_overlay_dectime">Average decoding time: %1$.2f ms</string>