Fix StyleSheet 'textAlign' for AndroidTextInput. Closes #2702

Summary:
change `setTextAlign` and `setTextAlignVertical` to receive argument of type `String` (the same as in `StyleSheet`), so that native props and stylesheet props are calling the same ReactMethod

- add demo (may not be necessary)
Closes https://github.com/facebook/react-native/pull/4481

Reviewed By: svcscm

Differential Revision: D2823456

Pulled By: mkonicek

fb-gh-sync-id: 349d17549f419b5bdc001d70b583423ade06bfe8

Libraries/Components/TextInput/TextInput.js

@@ -101,24 +101,6 @@ var TextInput = React.createClass({
      * The default value is false.
      */
     autoFocus: PropTypes.bool,
-    /**
-     * Set the position of the cursor from where editing will begin.
-     * @platform android
-     */
-    textAlign: PropTypes.oneOf([
-      'start',
-      'center',
-      'end',
-    ]),
-    /**
-     * Aligns text vertically within the TextInput.
-     * @platform android
-     */
-    textAlignVertical: PropTypes.oneOf([
-      'top',
-      'center',
-      'bottom',
-    ]),
     /**
      * If false, text is not editable. The default value is true.
      */
@@ -491,10 +473,6 @@ var TextInput = React.createClass({
 
     var autoCapitalize =
       UIManager.AndroidTextInput.Constants.AutoCapitalizationType[this.props.autoCapitalize];
-    var textAlign = UIManager.AndroidTextInput.Constants.TextAlign[this.props.textAlign];
-    var textAlignVertical =
-      UIManager.AndroidTextInput.Constants.TextAlignVertical[this.props.textAlignVertical];
-
     var children = this.props.children;
     var childCount = 0;
     ReactChildren.forEach(children, () => ++childCount);
@@ -512,8 +490,6 @@ var TextInput = React.createClass({
         style={[this.props.style]}
         autoCapitalize={autoCapitalize}
         autoCorrect={this.props.autoCorrect}
-        textAlign={textAlign}
-        textAlignVertical={textAlignVertical}
         keyboardType={this.props.keyboardType}
         mostRecentEventCount={0}
         multiline={this.props.multiline}