[SPARK-13153][PYSPARK] ML persistence failed when handle no default value parameter

Fix this defect by check default value exist or not.

yanboliang Please help to review.

Author: Tommy YU <tummyyu@163.com>

Closes #11043 from Wenpei/spark-13153-handle-param-withnodefaultvalue.

python/pyspark/ml/wrapper.py

@@ -79,8 +79,9 @@ class JavaWrapper(Params):
         for param in self.params:
             if self._java_obj.hasParam(param.name):
                 java_param = self._java_obj.getParam(param.name)
-                value = _java2py(sc, self._java_obj.getOrDefault(java_param))
-                self._paramMap[param] = value
+                if self._java_obj.isDefined(java_param):
+                    value = _java2py(sc, self._java_obj.getOrDefault(java_param))
+                    self._paramMap[param] = value
 
     @staticmethod
     def _empty_java_param_map():