[GOBBLIN-2071] Adds execution start timer to temporal (#3953)

diff --git a/gobblin-temporal/src/main/java/org/apache/gobblin/temporal/ddm/workflow/impl/ExecuteGobblinWorkflowImpl.java b/gobblin-temporal/src/main/java/org/apache/gobblin/temporal/ddm/workflow/impl/ExecuteGobblinWorkflowImpl.java
index 9d6776a..7760883 100644
--- a/gobblin-temporal/src/main/java/org/apache/gobblin/temporal/ddm/workflow/impl/ExecuteGobblinWorkflowImpl.java
+++ b/gobblin-temporal/src/main/java/org/apache/gobblin/temporal/ddm/workflow/impl/ExecuteGobblinWorkflowImpl.java
@@ -75,6 +75,7 @@
   @Override
   public ExecGobblinStats execute(Properties jobProps, EventSubmitterContext eventSubmitterContext) {
     TemporalEventTimer.Factory timerFactory = new TemporalEventTimer.Factory(eventSubmitterContext);
+    timerFactory.create(TimingEvent.LauncherTimings.JOB_PREPARE).submit();
     EventTimer timer = timerFactory.createJobTimer();
     try {
       int numWUsGenerated = genWUsActivityStub.generateWorkUnits(jobProps, eventSubmitterContext);