message: handle BarButton testID changing on Android
diff: import React from 'react';
  import { requireNativeComponent, Image, Platform, UIManager, StyleSheet } from 'react-native';
  -const BarButton = React.forwardRef<any, any>(({image, systemItem, show, search, style, children, ...props}, ref) => {
  +const BarButton = React.forwardRef<any, any>(({image, systemItem, show, search, style, children, testID, ...props}, ref) => {
  var constants = (UIManager as any).getViewManagerConfig('NVNavigationBar').Constants;
  return (Platform.OS === 'android' || !search) && (
  <NVBarButton
  ref={ref}
  - key={(Platform.OS === 'ios' && systemItem) || undefined}
  + key={Platform.OS === 'ios' ? systemItem : testID}
  + testID={testID}
  search={search}
  showActionView={!!children}
  showAsAction={Platform.OS === 'android' ? constants.ShowAsAction[show] : null}
  