Network Service memory metrics: fix expiration date

This was supposed to be "a year from now", not "now"

Bug: 962675, 962676
Change-Id: I8e135bec2bb6192c7dc3ae36e8362c87fa9ab892
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1610431
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Maks Orlovich <morlovich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659975}
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 359bb65..07a1345 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -57495,7 +57495,7 @@
 </histogram>
 
 <histogram base="true" name="Memory.Experimental.NetworkService2" units="MiB"
-    expires_after="2019-05-06">
+    expires_after="2020-05-06">
 <!-- Name completed by histogram_suffixes name="ProcessMemoryAllocator2" -->
 
   <owner>mmenke@chromium.org</owner>
@@ -57507,7 +57507,7 @@
 </histogram>
 
 <histogram base="true" name="Memory.Experimental.NetworkService2.Small"
-    units="KiB" expires_after="2019-05-06">
+    units="KiB" expires_after="2020-05-06">
 <!-- Name completed by histogram_suffixes name="ProcessMemoryAllocatorSmall2" -->
 
   <owner>mmenke@chromium.org</owner>
@@ -58426,7 +58426,7 @@
 </histogram>
 
 <histogram name="Memory.NetworkService.PrivateMemoryFootprint" units="MiB"
-    expires_after="2019-05-06">
+    expires_after="2020-05-06">
   <owner>mmenke@chromium.org</owner>
   <owner>morlovich@chromium.org</owner>
   <summary>
@@ -58436,7 +58436,7 @@
 </histogram>
 
 <histogram name="Memory.NetworkService.PrivateSwapFootprint" units="MiB"
-    expires_after="2019-05-06">
+    expires_after="2020-05-06">
   <owner>mmenke@chromium.org</owner>
   <owner>morlovich@chromium.org</owner>
   <summary>
@@ -58446,7 +58446,7 @@
 </histogram>
 
 <histogram name="Memory.NetworkService.ResidentSet" units="MiB"
-    expires_after="2019-05-06">
+    expires_after="2020-05-06">
   <owner>mmenke@chromium.org</owner>
   <owner>morlovich@chromium.org</owner>
   <summary>
@@ -58459,7 +58459,7 @@
 </histogram>
 
 <histogram name="Memory.NetworkService.SharedMemoryFootprint" units="MiB"
-    expires_after="2019-05-06">
+    expires_after="2020-05-06">
   <owner>mmenke@chromium.org</owner>
   <owner>morlovich@chromium.org</owner>
   <summary>