On a GCE host in the GCP project bad-food-17 with credentials for a service account in the project feisty-beverage-4711.
google-cloud-core 1.3.0 correctly defaults to the SA project:
GOOGLE_APPLICATION_CREDENTIALS=sa-key.json mvn -q compile exec:java -Dexec.mainClass=Repro -Dgoogle.cloud.core.version=1.3.0 | grep ServiceOptions.getDefaultProjectId
ServiceOptions.getDefaultProjectId(): feisty-beverage-4711
google-cloud-core 1.4.0+ incorrectly defaults to the GCE metadata project:
GOOGLE_APPLICATION_CREDENTIALS=sa-key.json mvn -q compile exec:java -Dexec.mainClass=Repro -Dgoogle.cloud.core.version=1.4.0 | grep ServiceOptions.getDefaultProjectId
ServiceOptions.getDefaultProjectId(): bad-food-17