Fix indentation issues reported by flake8

- E121 continuation line under-indented for hanging indent
- E122 continuation line missing indentation or outdented
- E125 continuation line with same indent as next logical line
- E126 continuation line over-indented for hanging indent
- E127 continuation line over-indented for visual indent
- E128 continuation line under-indented for visual indent
- E129 visually indented line with same indent as next logical line
- E131 continuation line unaligned for hanging indent

Fixed automatically with autopep8:

  git ls-files | grep py$ | xargs autopep8 --in-place \
    --select E121,E122,E125,E126,E127,E128,E129,E131

Change-Id: Ifd95fb8e6a1a4d6e9de187b5787d64a6326dd249
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254605
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: David Pursehouse <dpursehouse@collab.net>

subcmds/abandon.py

@@ -95,5 +95,5 @@ It is equivalent to "git branch -D <branchname>".
           result = "all project"
         else:
           result = "%s" % (
-            ('\n' + ' ' * width + '| ').join(p.relpath for p in success[br]))
+              ('\n' + ' ' * width + '| ').join(p.relpath for p in success[br]))
         print("%s%s| %s\n" % (br, ' ' * (width - len(br)), result), file=sys.stderr)