Fix various whitespace issues reported by pyflakes

- E201 whitespace after '['
- E202 whitespace before '}'
- E221 multiple spaces before operator
- E222 multiple spaces after operator
- E225 missing whitespace around operator
- E226 missing whitespace around arithmetic operator
- E231 missing whitespace after ','
- E261 at least two spaces before inline comment
- E271 multiple spaces after keyword

Fixed automatically with autopep8:

  git ls-files | grep py$ | xargs autopep8 --in-place \
    --select E201,E202,E221,E222,E225,E226,E231,E261,E271

Change-Id: I367113eb8c847eb460532c7c2f8643f33040308c
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254601
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: David Pursehouse <dpursehouse@collab.net>

manifest_xml.py

@@ -224,7 +224,7 @@ class XmlManifest(object):
     if self.notice:
       notice_element = root.appendChild(doc.createElement('notice'))
       notice_lines = self.notice.splitlines()
-      indented_notice = ('\n'.join(" "*4 + line for line in notice_lines))[4:]
+      indented_notice = ('\n'.join(" " * 4 + line for line in notice_lines))[4:]
       notice_element.appendChild(doc.createTextNode(indented_notice))
 
     d = self.default
@@ -855,7 +855,7 @@ class XmlManifest(object):
     if clone_depth:
       try:
         clone_depth = int(clone_depth)
-        if  clone_depth <= 0:
+        if clone_depth <= 0:
           raise ValueError()
       except ValueError:
         raise ManifestParseError('invalid clone-depth %s in %s' %