Use backticks not vertical bars to denote variables in comments for /examples

Bug: webrtc:12338
Change-Id: I753a476d1574d8dd50f1b6d4bfc2beb7f6f1f913
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226947
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34562}

examples/androidapp/src/org/appspot/apprtc/CallActivity.java

@@ -676,7 +676,7 @@ public class CallActivity extends Activity implements AppRTCClient.SignalingEven
     }
   }
 
-  // Log |msg| and Toast about it.
+  // Log `msg` and Toast about it.
   private void logAndToast(String msg) {
     Log.d(TAG, msg);
     if (logToast != null) {