autotest: refactor status_history into a lib outside of site_utils

CQ-DEPEND=CL:378599

BUG=chromium:641093
TEST=Ran dut_status command, verified working.

Change-Id: I9f60e2dff24683e66af00c7ce1c8a825b239e782
Reviewed-on: https://chromium-review.googlesource.com/378435
Commit-Ready: Aviv Keshet <[email protected]>
Tested-by: Aviv Keshet <[email protected]>
Reviewed-by: Richard Barnette <[email protected]>
diff --git a/site_utils/diagnosis_utils.py b/site_utils/diagnosis_utils.py
index bc8a97e..25abb06 100644
--- a/site_utils/diagnosis_utils.py
+++ b/site_utils/diagnosis_utils.py
@@ -14,7 +14,7 @@
 from autotest_lib.server import utils
 from autotest_lib.server.cros.dynamic_suite import reporting
 from autotest_lib.server.cros.dynamic_suite import reporting_utils
-from autotest_lib.site_utils import status_history
+from autotest_lib.server.lib import status_history
 
 
 class BoardNotAvailableError(utils.TestLabException):