Batch: fix job parameters definition (#8043)

Author: pinzon

moto/batch/models.py

@@ -639,7 +639,7 @@ def _add_parameters_to_command(self, command: Union[str, List[str]]) -> List[str
             return command
 
         new_command = [
-            command_part.replace(f"${param}", value)
+            command_part.replace(f"Ref::{param}", value)
             for command_part in command
             for param, value in self.parameters.items()
         ]

tests/test_batch/test_batch_jobs.py

@@ -1126,7 +1126,7 @@ def test_submit_job_with_parameters():
             "image": "busybox",
             "vcpus": 1,
             "memory": 512,
-            "command": ["sleep", "$seconds"],
+            "command": ["sleep", "Ref::seconds"],
         },
         parameters={"seconds": "0"},
     )