update unique resource id

Author: ohmayr

packages/google-cloud-firestore/tests/system/test__helpers.py

@@ -16,7 +16,7 @@
 MISSING_DOCUMENT = "No document to update: "
 DOCUMENT_EXISTS = "Document already exists: "
 ENTERPRISE_MODE_ERROR = "only allowed on ENTERPRISE mode"
-UNIQUE_RESOURCE_ID = unique_resource_id("-")
+UNIQUE_RESOURCE_ID = unique_resource_id("-") + "-" + str(os.getpid())
 EMULATOR_CREDS = EmulatorCreds()
 FIRESTORE_EMULATOR = os.environ.get(_FIRESTORE_EMULATOR_HOST) is not None
 FIRESTORE_OTHER_DB = os.environ.get("SYSTEM_TESTS_DATABASE", "system-tests-named-db")