get identity id: try to read from os environment

lisa/sut_orchestrator/azure/common.py

@@ -2734,6 +2734,9 @@ def get_managed_identity_object_id(
 def get_identity_id(
     platform: "AzurePlatform", application_id: Optional[str] = None
 ) -> Any:
+    if not application_id:
+        application_id = os.environ.get("AZURE_CLIENT_ID", "")
+
     if not application_id:
         # if the run machine resides on Azure
         # get the object ID of the managed identity