Remove animated prop

Summary:
This prop was deprecated in April 2016 in [this commit](2bb1c26#diff-931cea019b5e9faceffef4e46f1fff08), first in 0.26.0

It's been a while, we can remove it now.

Changelog:
[Breaking][General] Modal: Remove support for `aniamted` prop (deprecated in 0.26)

Reviewed By: cpojer

Differential Revision: D19762163

fbshipit-source-id: b6173bba066fc9ad0e786f56a946e2f3fa3d79cc

Author: elicwhite

Libraries/Modal/Modal.js

@@ -120,11 +120,6 @@ export type Props = $ReadOnly<{|
    */
   onDismiss?: ?() => mixed,
 
-  /**
-   * Deprecated. Use the `animationType` prop instead.
-   */
-  animated?: ?boolean,
-
   /**
    * The `supportedOrientations` prop allows the modal to be rotated to any of the specified orientations.
    *
@@ -212,14 +207,7 @@ class Modal extends React.Component<Props> {
       backgroundColor: this.props.transparent ? 'transparent' : 'white',
     };
 
-    let animationType = this.props.animationType;
-    if (!animationType) {
-      // manually setting default prop here to keep support for the deprecated 'animated' prop
-      animationType = 'none';
-      if (this.props.animated) {
-        animationType = 'slide';
-      }
-    }
+    let animationType = this.props.animationType || 'none';
 
     let presentationStyle = this.props.presentationStyle;
     if (!presentationStyle) {