autoupdate: Use correct nebraska.Request attributes event_type and event_results are properties of RequestApp not the Request itself. This patch fixes it. BUG=chromium:1014807 TEST=devserver_integration_test.py Change-Id: Ic0847ea198a4b0058c0e8cd46bd1c5e2f8d3ccc6 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1864310 Tested-by: Amin Hassani <ahassani@chromium.org> Auto-Submit: Amin Hassani <ahassani@chromium.org> Reviewed-by: Keith Haddow <haddowk@chromium.org> Commit-Queue: Keith Haddow <haddowk@chromium.org>