The angular.io project uses Angular and CLI v9, which by default turns
on Ivy mode. However, since ec4381dd4, we explicitly opt out of Ivy.
This commit removes the `enabledIvy: false` configuration, thus allowing
the default behavior of having Ivy on.
NOTE:
This commit only changes the angular.io projects. The docs examples need
to be updated separately (first to Angular and CLI v9 and then to Ivy).
PR Close#32923
George Kalpakas