dynamic_substitutions -> dynamicSubstitutions

cloudbuild.yaml

@@ -68,6 +68,6 @@ availableSecrets:
 options:
   machineType: 'E2_HIGHCPU_8'
   logging: CLOUD_LOGGING_ONLY
-  dynamic_substitutions: true
+  dynamicSubstitutions: true
 
 timeout: 1200s