migrations: Fix extra_data of RealmAuditLog objects.

This commit adds migration to fix extra_data field
of RealmAuditLog objects created on changing
can_remove_subscribers_group setting to add "property"
field since the same event type will now be used for
other group based stream settings that will be added
in future.

zerver/migrations/0430_fix_audit_log_objects_for_group_based_stream_settings.py

@@ -0,0 +1,50 @@
+# Generated by Django 4.1.6 on 2023-02-17 12:06
+import json
+
+from django.db import migrations
+from django.db.backends.postgresql.schema import BaseDatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+
+
+def fix_audit_log_objects_for_group_based_stream_settings(
+    apps: StateApps, schema_editor: BaseDatabaseSchemaEditor
+) -> None:
+    """
+    This adds the property_name field to any STREAM_GROUP_BASED_SETTING_CHANGED
+    audit log entries that were created before the previous commit.
+    """
+    RealmAuditLog = apps.get_model("zerver", "RealmAuditLog")
+
+    STREAM_GROUP_BASED_SETTING_CHANGED = 608
+    OLD_VALUE = "1"
+    NEW_VALUE = "2"
+
+    for audit_log_object in RealmAuditLog.objects.filter(
+        event_type=STREAM_GROUP_BASED_SETTING_CHANGED
+    ):
+        extra_data = json.loads(audit_log_object.extra_data)
+        old_value = extra_data[OLD_VALUE]
+        new_value = extra_data[NEW_VALUE]
+
+        audit_log_object.extra_data = json.dumps(
+            {
+                OLD_VALUE: old_value,
+                NEW_VALUE: new_value,
+                "property": "can_remove_subscribers_group",
+            }
+        )
+        audit_log_object.save(update_fields=["extra_data"])
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0429_user_topic_case_insensitive_unique_toghether"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            fix_audit_log_objects_for_group_based_stream_settings,
+            reverse_code=migrations.RunPython.noop,
+            elidable=True,
+        ),
+    ]