[SPARK-14104][PYSPARK][ML] All Python param setters should use the `_set` method

## What changes were proposed in this pull request?

Param setters in python previously accessed the _paramMap directly to update values. The `_set` method now implements type checking, so it should be used to update all parameters. This PR eliminates all direct accesses to `_paramMap` besides the one in the `_set` method to ensure type checking happens.

Additional changes:
* [SPARK-13068](https://github.com/apache/spark/pull/11663) missed adding type converters in evaluation.py so those are done here
* An incorrect `toBoolean` type converter was used for StringIndexer `handleInvalid` param in previous PR. This is fixed here.

## How was this patch tested?

Existing unit tests verify that parameters are still set properly. No new functionality is actually added in this PR.

Author: sethah <seth.hendrickson16@gmail.com>

Closes #11939 from sethah/SPARK-14104.

1 files changed, 1 insertions, 1 deletions

diff --git a/python/pyspark/ml/wrapper.py b/python/pyspark/ml/wrapper.py
index cd0e5b80d5..055a2816f8 100644
--- a/python/pyspark/ml/wrapper.py
+++ b/python/pyspark/ml/wrapper.py
@@ -112,7 +112,7 @@ class JavaParams(JavaWrapper, Params):
                 java_param = self._java_obj.getParam(param.name)
                 if self._java_obj.isDefined(java_param):
                     value = _java2py(sc, self._java_obj.getOrDefault(java_param))
-                    self._paramMap[param] = value
+                    self._set(**{param.name: value})
 
     def _transfer_param_map_from_java(self, javaParamMap):
         """