Holistic testing: sketching blocks GUI thread

[mfunk]

From Pro Intel Holistic testing on 8/9/2019:

onenote:///\tahoe\holistic\ArcGISProfessional\Srinivas\Pro_v2_5\ProInternalHolistic_v2_5\August2019\Friday_08_09_2019.one#Pro%20for%20Intel&section-id={F5163543-00ED-4E04-962A-EF349811C6D0}&page-id={495373F4-9079-4A22-A025-E02A20F312F4}&end

Row 5, Tester Max:

[lfunkhouser]

Add progress bar for more than 15 rings.