These changes include
- Remove the usage of `enableProdMode`
- Remove `test.ts`, `polyfills.ts`, `karma.conf.js` and environment files which are no longer generated by default
PR Close#47904
add the ariaCurrentWhenActive input to the RouterLinkActive directive so that
users can easily set the aria-current property to their active router
links
resolves#35051
PR Close#45167
https://developer.mozilla.org/en-US/docs/Web/CSS/font-family
"You should always include at least one generic family name in a font-family list,
since there's no guarantee that any given font is available. This lets the browser
select an acceptable fallback font when necessary."
PR Close#40254
