Warn for ARIA typos on custom elements

Normally we allow any attribute/property on custom elements. However it's
a shared namespace. The `aria-` namespace applies to all generic elements
which are shared with custom elements. So arguably adding custom extensions
there is a really bad idea since it can conflict with future additions.

It's possible there is a new standard one that's polyfilled by a custom
element but the same issue applies to React in general that we might
warn for very new additions so we just have to be quick on that.

Author: sebmarkbage

packages/react-dom-bindings/src/shared/ReactDOMInvalidARIAHook.js

@@ -6,7 +6,6 @@
  */
 
 import {ATTRIBUTE_NAME_CHAR} from './isAttributeNameSafe';
-import isCustomComponent from './isCustomComponent';
 import validAriaProperties from './validAriaProperties';
 import hasOwnProperty from 'shared/hasOwnProperty';
 
@@ -110,8 +109,5 @@ function warnInvalidARIAProps(type, props) {
 }
 
 export function validateProperties(type, props) {
-  if (isCustomComponent(type, props)) {
-    return;
-  }
   warnInvalidARIAProps(type, props);
 }