reset command for each run invocation

Author: guoqiao1992

src/sagemaker/spark/processing.py

@@ -737,7 +737,8 @@ def run(
                 user code file (default: None).
         """
         self._current_job_name = self._generate_current_job_name(job_name=job_name)
-
+        self.command = [_SparkProcessorBase._default_command]
+        
         if not submit_app:
             raise ValueError("submit_app is required")
 
@@ -917,6 +918,7 @@ def run(
                 user code file (default: None).
         """
         self._current_job_name = self._generate_current_job_name(job_name=job_name)
+        self.command = [_SparkProcessorBase._default_command]
 
         if not submit_app:
             raise ValueError("submit_app is required")