Fix and enable dangerous-default-value lint

The fix is more of an elision and the code in the changed area is
reflowed.

.pylintrc

@@ -32,6 +32,5 @@
 #TODO: Enable simplifiable-if-statement
 #TODO: Enable no-self-use
 #TODO: Enable no-member
-#TODO: Enable dangerous-default-value
 
-disable=missing-docstring,too-few-public-methods,too-many-arguments,no-init,duplicate-code,invalid-name,suppressed-message,locally-disabled,protected-access,no-name-in-module,unused-argument,fixme,wrong-import-order,no-value-for-parameter,cyclic-import,unused-variable,redefined-outer-name,unused-import,too-many-instance-attributes,broad-except,too-many-locals,too-many-lines,redefined-variable-type,next-method-called,import-error,useless-else-on-loop,too-many-return-statements,too-many-nested-blocks,super-init-not-called,simplifiable-if-statement,no-self-use,no-member,dangerous-default-value
+disable=missing-docstring,too-few-public-methods,too-many-arguments,no-init,duplicate-code,invalid-name,suppressed-message,locally-disabled,protected-access,no-name-in-module,unused-argument,fixme,wrong-import-order,no-value-for-parameter,cyclic-import,unused-variable,redefined-outer-name,unused-import,too-many-instance-attributes,broad-except,too-many-locals,too-many-lines,redefined-variable-type,next-method-called,import-error,useless-else-on-loop,too-many-return-statements,too-many-nested-blocks,super-init-not-called,simplifiable-if-statement,no-self-use,no-member

src/python/grpcio/grpc/_common.py

@@ -153,13 +153,7 @@ class CleanupThread(threading.Thread):
     we accomplish this by overriding the join() method.
     """
 
-    def __init__(self,
-                 behavior,
-                 group=None,
-                 target=None,
-                 name=None,
-                 args=(),
-                 kwargs={}):
+    def __init__(self, behavior, *args, **kwargs):
         """Constructor.
 
         Args:
@@ -167,17 +161,10 @@ class CleanupThread(threading.Thread):
                 argument, timeout, indicating the maximum duration of
                 `behavior`, or None indicating `behavior` has no deadline.
                 `behavior` must be idempotent.
-      group (None): should be None.  Reseved for future extensions
-          when ThreadGroup is implemented.
-      target (function): The function to invoke when this thread is
-          run.  Defaults to None.
-      name (str): The name of this thread.  Defaults to None.
-        args (tuple[object]): A tuple of arguments to pass to `target`.
-      kwargs (dict[str,object]): A dictionary of keyword arguments to
-           pass to `target`.
+            args: Positional arguments passed to threading.Thread constructor.
+            kwargs: Keyword arguments passed to threading.Thread constructor.
         """
-        super(CleanupThread, self).__init__(
-            group=group, target=target, name=name, args=args, kwargs=kwargs)
+        super(CleanupThread, self).__init__(*args, **kwargs)
         self._behavior = behavior
 
     def join(self, timeout=None):