update_engine: run gn format BUILD.gn and *.gni

Run gn format **/BUILD.gn and **/*.gni to apply new format of uprev'd gn
of version "1733 (82d673ac)".

BUG=chromium:1072321
TEST=cros tryjob -g 2156088 -g 2126033 hatch-full-tryjob

Cq-Depend: chromium:2126033
Change-Id: Ib42a47d6e1d8c564e1f08e1caa16fbb7d0620030
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2156088
Tested-by: Clark Chung <ckclark@chromium.org>
Commit-Queue: Clark Chung <ckclark@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/tar_bunzip2.gni b/tar_bunzip2.gni
index 0a17899..5d90167 100644
--- a/tar_bunzip2.gni
+++ b/tar_bunzip2.gni
@@ -21,9 +21,7 @@
   action_foreach(target_name) {
     sources = invoker.sources
     script = "//common-mk/file_generator_wrapper.py"
-    outputs = [
-      "${out_dir}/{{source_name_part}}.flag",
-    ]
+    outputs = [ "${out_dir}/{{source_name_part}}.flag" ]
     args = [
       "sh",
       "-c",