[Cobalt] Remove realm Metric Dimensions

Remove the realm metric dimensions from
set_software_distribution_info_called_migrated in Cobalt Internal
Metrics.

Bug: b/262599427
Change-Id: I852d1c68f0351bec29dac9546ee9c9ec7db12035
Reviewed-on: https://fuchsia-review.googlesource.com/c/cobalt-registry/+/778102
Reviewed-by: Cameron Dale <camrdale@google.com>
Privacy-Approval: Cameron Dale <camrdale@google.com>
Commit-Queue: Andrew Hwang <anhwang@google.com>
diff --git a/cobalt_internal/metrics/metrics.yaml b/cobalt_internal/metrics/metrics.yaml
index b5a43b5..de62f13 100644
--- a/cobalt_internal/metrics/metrics.yaml
+++ b/cobalt_internal/metrics/metrics.yaml
@@ -286,7 +286,7 @@
 # set_software_distribution_info_called_migrated
 #
 # Whenever the SetSoftwareDistributionInfo() method from the SystemDataUpdater interface is
-# invoked, we log "1" along with an indication of the current and new channels and realms.
+# invoked, we log "1" along with an indication of the current and new channels.
 #####################################################################
 - id: 110
   metric_name: set_software_distribution_info_called_migrated
@@ -303,23 +303,7 @@
         0: Unset    # SetSoftwareDistributionInfo was not called before.
         1: Unknown  # SetSoftwareDistributionInfo called with null channel.
         2: Valid    # SetSoftwareDistributionInfo called with channel string.
-    - dimension: new_realm
-      event_codes:
-        0: Unset
-        1: Unknown
-        2: Valid
-    - dimension: previous_realm
-      event_codes:
-        0: Unset    # SetSoftwareDistributionInfo was not called before.
-        1: Unknown  # SetSoftwareDistributionInfo called with null realm.
-        2: Valid    # SetSoftwareDistributionInfo called with realm string.
   reports:
-    - report_name: stats_per_device_realm
-      id: 1
-      report_type: UNIQUE_DEVICE_NUMERIC_STATS
-      privacy_level: NO_ADDED_PRIVACY
-      system_profile_field: [PRODUCT_NAME]
-      local_aggregation_period: WINDOW_1_DAY
     - report_name: stats_per_device_channel
       id: 2
       report_type: UNIQUE_DEVICE_NUMERIC_STATS
@@ -338,6 +322,10 @@
           num_buckets: 25
       local_aggregation_period: WINDOW_1_DAY
       system_profile_field: [BOARD_NAME, PRODUCT_NAME, SYSTEM_VERSION, CHANNEL]
+
+  # Deleted report IDs that must not be reused.
+  deleted_report_ids: [1]
+
   meta_data:
     max_release_stage: GA
     expiration_date: "2023/05/06"