Add missing ostream includes.

These compilation units had a transitive dependency on ostream via
base/numerics/safe_conversions.h. The ostream include in
safe_conversions.h is however unused and should be removed.

This CL was uploaded by git cl split.

R=shaochuan@chromium.org

Bug: 1270812, 1372522
Change-Id: Ia2f3574b08298db21bdee07f455c3069f896132b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4057286
Commit-Queue: Shao-Chuan Lee <shaochuan@chromium.org>
Auto-Submit: Jean-Philippe Gravel <jpgravel@chromium.org>
Reviewed-by: Shao-Chuan Lee <shaochuan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1075878}

ash/components/arc/metrics/stability_metrics_manager.cc

@@ -4,6 +4,8 @@
 
 #include "ash/components/arc/metrics/stability_metrics_manager.h"
 
+#include <ostream>
+
 #include "ash/components/arc/arc_prefs.h"
 #include "base/metrics/histogram_macros.h"
 #include "components/prefs/pref_service.h"