Fix missing props (#2179)

Fix props loading from PropsRegistry in custom buttons

src/Navigation.js

       constructor(props) {
         super(props);
         this.state = {
-          internalProps: {...props, ...PropRegistry.load(props.screenInstanceID)}
+          internalProps: {...props, ...PropRegistry.load(props.screenInstanceID || props.passPropsKey)}
         }
       }
 
       componentWillReceiveProps(nextProps) {
         this.setState({
-          internalProps: {...PropRegistry.load(this.props.screenInstanceID), ...nextProps}
+          internalProps: {...PropRegistry.load(this.props.screenInstanceID || this.props.passPropsKey), ...nextProps}
         })
       }
 

src/deprecated/platformSpecificDeprecated.android.js

 import React, {Component} from 'react';
 import ReactNative, {AppRegistry, NativeModules, processColor} from 'react-native';
 import _ from 'lodash';
+import PropRegistry from './../PropRegistry';
 
 import Navigation from './../Navigation';
 
       if (button.buttonColor) {
         button.color = processColor(button.buttonColor);
       }
+      if (button.component) {
+        const passPropsKey = _.uniqueId('customButtonComponent');
+        PropRegistry.save(passPropsKey, button.passProps);
+        button.passProps = {passPropsKey};
+      }
     });
   }
   let leftButton = getLeftButton(params);