isort: format codebase

Change-Id: I6f11d123b68fd077f558d3c21349c55c5f251019
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/383715
Reviewed-by: Gavin Mak <gavinmak@google.com>
Tested-by: Mike Frysinger <vapier@google.com>
Commit-Queue: Mike Frysinger <vapier@google.com>
diff --git a/git_command.py b/git_command.py
index 36fcfe7..a5cf514 100644
--- a/git_command.py
+++ b/git_command.py
@@ -14,17 +14,20 @@
 
 import functools
 import os
-import sys
 import subprocess
+import sys
 from typing import Any, Optional
 
 from error import GitError
 from error import RepoExitError
 from git_refs import HEAD
 import platform_utils
-from repo_trace import REPO_TRACE, IsTrace, Trace
+from repo_trace import IsTrace
+from repo_trace import REPO_TRACE
+from repo_trace import Trace
 from wrapper import Wrapper
 
+
 GIT = "git"
 # NB: These do not need to be kept in sync with the repo launcher script.
 # These may be much newer as it allows the repo launcher to roll between