AWSBillingConductor: Add support for Passthrough pricing plan

Author: aws-sdk-java-automation

.changes/next-release/feature-AWSBillingConductor-99db8eb.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "AWSBillingConductor",
+    "contributor": "",
+    "description": "Add support for Passthrough pricing plan"
+}

services/billingconductor/src/main/resources/codegen-resources/service-2.json

@@ -2686,7 +2686,7 @@
     },
     "PricingPlanArn":{
       "type":"string",
-      "pattern":"(arn:aws(-cn)?:billingconductor::(aws|[0-9]{12}):pricingplan/)?(BasicPricingPlan|[a-zA-Z0-9]{10})"
+      "pattern":"(arn:aws(-cn)?:billingconductor::(aws|[0-9]{12}):pricingplan/)?(BasicPricingPlan|Passthrough|[a-zA-Z0-9]{10})"
     },
     "PricingPlanArns":{
       "type":"list",
@@ -2702,7 +2702,7 @@
     },
     "PricingPlanFullArn":{
       "type":"string",
-      "pattern":"arn:aws(-cn)?:billingconductor::(aws|[0-9]{12}):pricingplan/(BasicPricingPlan|[a-zA-Z0-9]{10})"
+      "pattern":"arn:aws(-cn)?:billingconductor::(aws|[0-9]{12}):pricingplan/(BasicPricingPlan|Passthrough|[a-zA-Z0-9]{10})"
     },
     "PricingPlanList":{
       "type":"list",