fix(storage): remove unused variables

Author: HemangChothani

google/cloud/storage/_helpers.py

@@ -312,8 +312,6 @@ def update(
  self,
  client=None,
  timeout=_DEFAULT_TIMEOUT,
- if_generation_match=None,
- if_generation_not_match=None,
  if_metageneration_match=None,
  if_metageneration_not_match=None,
  ):
@@ -335,18 +333,6 @@ def update(
  Can also be passed as a tuple (connect_timeout, read_timeout).
  See :meth:`requests.Session.request` documentation for details.
 
- :type if_generation_match: long
- :param if_generation_match: (Optional) Make the operation conditional on whether
- the blob's current generation matches the given value.
- Setting to 0 makes the operation succeed only if there
- are no live versions of the blob.
-
- :type if_generation_not_match: long
- :param if_generation_not_match: (Optional) Make the operation conditional on whether
- the blob's current generation does not match the given
- value. If no live blob exists, the precondition fails.
- Setting to 0 makes the operation succeed only if there
- is a live version of the blob.
 
  :type if_metageneration_match: long
  :param if_metageneration_match: (Optional) Make the operation conditional on whether the