[GSS](7.3.z) HAL-1649 - HAL Management Console black screen - Syntax Error in polyfill.min.js with IE 11

• Not able see Management Console
• Blank Browser screen, but works in other browsers
• Browser Console shows Syntax Error in "polyfill.min.js" (85,1) and "'fetch' is undefined" external.min.js (15660,52015) among other errors

At that line in polyfill.min.js, there appears to be a "export function Headers(headers)". I don't think that's valid syntax.

It seems related to this issue with fetch https://github.com/github/fetch/issues/656, which they said can be fixed by using the UMD version.

This issue https://issues.jboss.org/browse/HAL-1484, suggests that the polyfills were added for IE 11, but it clearly doesn't work even in 7.2.0.