cros_ml: Extend diagnostic histogram

Fixed: b:367340314
Change-Id: I3f06884834190071bd087d6128459f7b9922cc03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5869649
Auto-Submit: Andrew Moylan <amoylan@google.com>
Commit-Queue: Andrew Moylan <amoylan@google.com>
Reviewed-by: Tony Yeoman <tby@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1356290}
diff --git a/tools/metrics/histograms/metadata/cros_ml/histograms.xml b/tools/metrics/histograms/metadata/cros_ml/histograms.xml
index f718bcf..86b7a60 100644
--- a/tools/metrics/histograms/metadata/cros_ml/histograms.xml
+++ b/tools/metrics/histograms/metadata/cros_ml/histograms.xml
@@ -97,7 +97,7 @@
 
 <histogram name="MachineLearningService.HandwritingModel.LoadModelResult.Event"
     enum="MachineLearningServiceLoadHandwritingModelResultEvent"
-    expires_after="2024-10-28">
+    expires_after="2025-04-01">
   <owner>amoylan@chromium.org</owner>
   <owner>alanlxl@chromium.org</owner>
   <owner>charleszhao@chromium.org</owner>