Dependency cleanup: Move test.utils.ResetCommitTime to utils.sys_utils.

The ResetCommitTime uses only standard Python module and utils API and
can be in sys_utils. This helps to prevent pulling extra dependency.

BUG=chromium:403712
TEST=make test

Change-Id: Icc20fa14679959360ca45ae21fa55773d32bb277
Reviewed-on: https://chromium-review.googlesource.com/321031
Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Wei-Han Chen <stimim@chromium.org>
diff --git a/py/goofy/goofy.py b/py/goofy/goofy.py
index 1967b90..49f1516 100755
--- a/py/goofy/goofy.py
+++ b/py/goofy/goofy.py
@@ -332,7 +332,7 @@
     # Before starting state server, remount stateful partitions with
     # no commit flag.  The default commit time (commit=600) makes corruption
     # too likely.
-    utils.ResetCommitTime()
+    sys_utils.ResetCommitTime()
 
     self.state_instance, self.state_server = (
         state.create_server(bind_address='0.0.0.0'))