VideoCapturerAndroid: Revert elapsedRealtimeNanos to elapsedRealtime

Review URL: https://codereview.webrtc.org/1254143002

Cr-Commit-Position: refs/heads/master@{#9637}
diff --git a/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java b/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
index 8976ad2..d1e4570 100644
--- a/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
+++ b/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
@@ -805,7 +805,8 @@
       throw new RuntimeException("Unexpected camera in callback!");
     }
 
-    final long captureTimeNs = SystemClock.elapsedRealtimeNanos();
+    final long captureTimeNs =
+        TimeUnit.MILLISECONDS.toNanos(SystemClock.elapsedRealtime());
 
     captureBuffersCount += videoBuffers.numCaptureBuffersAvailable();
     int rotation = getDeviceOrientation();