[histogram] Extend lifetime of some diagnostic metrics.

Extend expiry dates for following metric:
 . Graphics.PresentationTimestamp.InvalidBeforeSwap
 . Graphics.PresentationTimestamp.InvalidFromFuture
 . Graphics.PresentationTimestamp.LargePresentationDelta

BUG=1167839

Change-Id: I5ae2de4e7611cda9bdd614a740737fb6acea1a2d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2716168
Auto-Submit: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Brian White <bcwhite@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#857333}

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -6254,7 +6254,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Graphics.PresentationTimestamp.InvalidBeforeSwap" units="ms"
-    expires_after="2021-03-01">
+    expires_after="2021-09-01">
   <owner>sadrul@chromium.org</owner>
   <owner>graphics-dev@chromium.org</owner>
   <summary>
@@ -6267,7 +6267,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Graphics.PresentationTimestamp.InvalidFromFuture" units="ms"
-    expires_after="2021-03-01">
+    expires_after="2021-09-01">
   <owner>sadrul@chromium.org</owner>
   <owner>graphics-dev@chromium.org</owner>
   <summary>
@@ -6279,7 +6279,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Graphics.PresentationTimestamp.LargePresentationDelta"
-    units="ms" expires_after="2021-03-01">
+    units="ms" expires_after="2021-09-01">
   <owner>sadrul@chromium.org</owner>
   <owner>graphics-dev@chromium.org</owner>
   <summary>