Update OAS for Preview (#130)

Co-authored-by: update-oas-bot <update-oas-bot]@users.noreply.github.com>

Author: github-actions[bot]

api-specifications/retailmedia_preview.json

@@ -15630,7 +15630,7 @@
             "x-optional-in-response": true
           },
           "campaignId": {
-            "type": "integer",
+            "type": "string",
             "format": "int64"
           },
           "createdAt": {
@@ -15684,15 +15684,15 @@
           },
           "status": {
             "enum": [
-              "Unknown",
-              "Active",
-              "Scheduled",
-              "Draft",
-              "Paused",
-              "BudgetHit",
-              "Ended",
-              "Archived",
-              "NoFunds"
+              "unknown",
+              "active",
+              "scheduled",
+              "draft",
+              "paused",
+              "budgetHit",
+              "ended",
+              "archived",
+              "noFunds"
             ],
             "type": "string",
             "description": "Status of a line item.",
@@ -15706,7 +15706,7 @@
             "x-optional-in-response": true
           },
           "targetRetailerId": {
-            "type": "integer",
+            "type": "string",
             "format": "int64"
           },
           "updatedAt": {
@@ -15794,7 +15794,7 @@
             "nullable": true
           },
           "targetRetailerId": {
-            "type": "integer",
+            "type": "string",
             "format": "int64"
           }
         },