Fix TestAccEventarcGoogleChannelConfig_cryptoKeyUpdate to properly cl…

…ean up (GoogleCloudPlatform#7479)

mmv1/third_party/terraform/tests/resource_eventarc_google_channel_config_test.go.erb

@@ -76,6 +76,9 @@ func TestAccEventarcGoogleChannelConfig_cryptoKeyUpdate(t *testing.T) {
 				ImportState:       true,
 				ImportStateVerify: true,
 			},
+			{
+				Config: testAccEventarcGoogleChannelConfig_deleteCryptoKey(context),
+			},
 		},
 	})
 }
@@ -153,6 +156,16 @@ resource "google_eventarc_google_channel_config" "primary" {
 	`, context)
 }
 
+func testAccEventarcGoogleChannelConfig_deleteCryptoKey(context map[string]interface{}) string {
+	return Nprintf(`
+resource "google_eventarc_google_channel_config" "primary" {
+	location = "%{region}"
+	name     = "projects/%{project_name}/locations/%{region}/googleChannelConfig"
+	crypto_key_name = ""
+}
+	`, context)
+}
+
 func testAccCheckEventarcGoogleChannelConfigDestroyProducer(t *testing.T) func(s *terraform.State) error {
 	return func(s *terraform.State) error {
 		for name, rs := range s.RootModule().Resources {