use extendedStage for Builder wrapper

refs DE-338

[canvas-builds-refspec=e12b0f989dc38492981a9f286e079afc70e24cd5]

Change-Id: I1fd2647d5ef6e9cc4714daac0433c29b1939e156
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/261323
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
QA-Review: Aaron Ogata <aogata@instructure.com>
Product-Review: Aaron Ogata <aogata@instructure.com>
Reviewed-by: Kyle Rosenbaum <krosenbaum@instructure.com>

Jenkinsfile

@@ -313,6 +313,7 @@ library "canvas-builds-library@${getCanvasBuildsRefspec()}"
 
 configuration.setUseCommitMessageFlags(env.GERRIT_EVENT_TYPE != 'change-merged')
 extendedStage.setAlwaysAllowStages([
+    'Builder',
     'Setup',
     'Rebase',
     'Build Docker Image',
@@ -419,8 +420,7 @@ pipeline {
 
           def rootStages = [:]
 
-          rootStages['Builder'] = {
-            stage('Builder') {
+          extendedStage.withOptions('Builder', rootStages, extendedStage.DISABLE_MEASURE_TIMINGS) {
             // Use a nospot instance for now to avoid really bad UX. Jenkins currently will
             // wait for the current steps to complete (even wait to spin up a node), causing
             // extremely long wait times for a restart. Investigation in DE-166 / DE-158.
@@ -817,7 +817,6 @@ pipeline {
               }
             }
           }
-          }
 
           parallel(rootStages)
         }//script