Extend expiration of ImageFetcher and Dark SRP related histograms

Bug: 1140009, 1140047, 1140048, 1140049
Change-Id: Ic076b3f15bf7d8b243ee35ac4348eefa87292a44
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485214Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Filip Gorski <fgorski@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Brandon Wylie <wylieb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818980}

tools/metrics/histograms/histograms_xml/android/histograms.xml

@@ -397,7 +397,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Android.DarkTheme.DarkSearchRequested" enum="Boolean"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>wylieb@chromium.org</owner>
   <owner>twellington@chromium.org</owner>
   <owner>chrome-android-app@chromium.org</owner>

tools/metrics/histograms/histograms_xml/image/histograms.xml

@@ -248,7 +248,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.Events" enum="ImageFetcherEvent"
-    expires_after="2021-02-14">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -259,7 +259,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.ImageLoadFromCacheTime" units="ms"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -269,7 +269,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.ImageLoadFromCacheTimeJava" units="ms"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -279,7 +279,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.ImageLoadFromNativeTimeJava" units="ms"
-    expires_after="2021-02-14">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -289,7 +289,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.ImageLoadFromNetworkAfterCacheHit" units="ms"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -299,7 +299,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.ImageLoadFromNetworkTime" units="ms"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -309,7 +309,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.LoadImageMetadata" units="ms"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -318,7 +318,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.RequestStatusCode"
-    enum="CombinedHttpResponseAndNetErrorCode" expires_after="2021-02-14">
+    enum="CombinedHttpResponseAndNetErrorCode" expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>
@@ -329,7 +329,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ImageFetcher.TimeSinceLastCacheLRUEviction" units="ms"
-    expires_after="2020-12-01">
+    expires_after="2021-06-01">
   <owner>fgorski@chromium.org</owner>
   <owner>wylieb@chromium.org</owner>
   <summary>