Add another error code to the list of unregistered RP errors (Azure#21606)

Author: jhendrixMSFT

sdk/azcore/CHANGELOG.md

@@ -13,6 +13,8 @@
 
 ### Bugs Fixed
 
+* Fixed an issue that could cause some ARM RPs to not be automatically registered.
+
 ### Other Changes
 
 ## 1.8.0-beta.3 (2023-09-07)

sdk/azcore/arm/runtime/policy_register_rp.go

@@ -176,6 +176,7 @@ var unregisteredRPCodes = []string{
 	"MissingSubscriptionRegistration",
 	"MissingRegistrationForResourceProvider",
 	"Subscription Not Registered",
+	"SubscriptionNotRegistered",
 }
 
 func isUnregisteredRPCode(errorCode string) bool {

sdk/azcore/arm/runtime/policy_register_rp_test.go

@@ -414,6 +414,7 @@ func TestRPRegistrationPolicyEnvironmentsInSubExceeded(t *testing.T) {
 
 func TestIsUnregisteredRPCode(t *testing.T) {
 	require.True(t, isUnregisteredRPCode("Subscription Not Registered"))
+	require.True(t, isUnregisteredRPCode("SubscriptionNotRegistered"))
 	require.False(t, isUnregisteredRPCode("Your subscription isn't registered"))
 }