Set the Quick fix build token if the device is enterprise enrolled

Checks whether the DeviceQuickFixBuildToken has been set when :
- device is enterprise enrolled
- device has the policy been set

BUG=chromium:962467
TEST=./build_packages --board=amd64-generic && \
cros_run_unit_tests --board=amd64-generic --packages update_engine

Change-Id: Ie65167f7a83577256ee4bbfb07ea19ee4e4c6401
Reviewed-on: https://chromium-review.googlesource.com/1611549
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Amr Aboelkher <amraboelkher@google.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/update_attempter.cc b/update_attempter.cc
index d97917a..fcafd56 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -428,7 +428,8 @@
   omaha_request_params_->set_dlc_module_ids(dlc_module_ids_);
   omaha_request_params_->set_is_install(is_install_);
 
-  // Set Quick Fix Build token if policy is set.
+  // Set Quick Fix Build token if policy is set and the device is enterprise
+  // enrolled.
   string token;
   if (system_state_ && system_state_->device_policy()) {
     if (!system_state_->device_policy()->GetDeviceQuickFixBuildToken(&token))