HPCC-9254 Dynamic timeActivities for Roxie - to reduce get_cycles_now() overhead

Signed-off-by: Mark Kelly <mark.kelly@lexisnexis.com>

Made changes to not call virtual function every time.

roxie/ccd/ccdcontext.cpp

@@ -2576,6 +2576,7 @@ protected:
         ctxPrefetchProjectPreload = defaultPrefetchProjectPreload;
 
         traceActivityTimes = false;
+        timeActivities = defaultTimeActivities;
     }
 
     void startWorkUnit()