Change main histogram owner for ContentVerification.FetchNetError

It's a fixup for https://crrev.com/c/2426583. We've decided to have burunduk@
at the main histogram owner, but forgot to upload a patch for that.

Bug: None
Change-Id: I4cb2777e931376a2f9dbc7a2c28dc64618e0c03c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2498566
Auto-Submit: Oleg Davydov <burunduk@chromium.org>
Commit-Queue: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821020}

tools/metrics/histograms/histograms_xml/extensions/histograms.xml

@@ -385,8 +385,8 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Extensions.ContentVerification.FetchFailureError"
     enum="CombinedHttpResponseAndNetErrorCode" expires_after="2021-03-30">
-  <owner>lazyboy@chromium.org</owner>
   <owner>burunduk@chromium.org</owner>
+  <owner>lazyboy@chromium.org</owner>
   <owner>rdevlin.cronin@chromium.org</owner>
   <owner>extensions-core@chromium.org</owner>
   <summary>