lint: api: sort imports

After configuring sort behavior in isort.cfg, run `./scripts/isort`
on all the api/ modules in the tree.

BUG=b:187788732
TEST=`cros lint` is clean

Change-Id: I838009ea70ff52a1560a597509909c0b514247b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3615052
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Alex Klein <saklein@chromium.org>
diff --git a/api/compile_build_api_proto.py b/api/compile_build_api_proto.py
index a8ca4c7..4a0f70d 100644
--- a/api/compile_build_api_proto.py
+++ b/api/compile_build_api_proto.py
@@ -19,6 +19,7 @@
 from chromite.lib import git
 from chromite.lib import osutils
 
+
 _CIPD_ROOT = os.path.join(constants.CHROMITE_DIR, '.cipd_bin')
 
 # Chromite's protobuf library version (third_party/google/protobuf).