fix(upgrade): Prevent property renaming for $inject.

Switch to bracket notation for `directiveFactory.$inject`, otherwise Closure Compiler will (property) rename it, since the output type is `any`.

modules/@angular/upgrade/src/common/downgrade_component.ts

@@ -124,7 +124,8 @@ export function downgradeComponent(info: /* ComponentInfo */ {
     };
   };
 
-  directiveFactory.$inject = [$COMPILE, $INJECTOR, $PARSE];
+  // bracket-notation because of closure - see #14441
+  directiveFactory['$inject'] = [$COMPILE, $INJECTOR, $PARSE];
   return directiveFactory;
 }