UpdateManager: Do not schedule update checks if OOBE did not complete.

This abides by the current logic, as found in
UpdateCheckScheduler::StaticCheck().  New unit test added to verify this
behavior.

BUG=chromium:358269
TEST=Unit tests.

Change-Id: I747e8a59408d6b93ceea62ef741b36e09f937a08
Reviewed-on: https://chromium-review.googlesource.com/207241
Reviewed-by: Alex Deymo <deymo@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
diff --git a/update_manager/chromeos_policy.h b/update_manager/chromeos_policy.h
index b7bbdfc..75e31cc 100644
--- a/update_manager/chromeos_policy.h
+++ b/update_manager/chromeos_policy.h
@@ -67,6 +67,7 @@
   FRIEND_TEST(UmChromeOSPolicyTest, RecurringCheckBackoffIntervalAndFuzz);
   FRIEND_TEST(UmChromeOSPolicyTest, ExponentialBackoffIsCapped);
   FRIEND_TEST(UmChromeOSPolicyTest, UpdateCheckAllowedWaitsForTheTimeout);
+  FRIEND_TEST(UmChromeOSPolicyTest, UpdateCheckAllowedWaitsForOOBE);
   FRIEND_TEST(UmChromeOSPolicyTest,
               UpdateCanStartNotAllowedScatteringNewWaitPeriodApplies);
   FRIEND_TEST(UmChromeOSPolicyTest,