message: Implemented nav icon accessibility label prop
  Copied from toolbar manager
diff: @@ -30,6 +30,11 @@ public class SearchToolbarManager extends ViewGroupManager<SearchToolbarView> {
  view.setNavIconSource(navIcon);
  }
  + @ReactProp(name = "navigationAccessibilityLabel")
  + public void setNavigationContentDescription(SearchToolbarView view, String navigationContentDescription) {
  + view.setNavigationContentDescription(navigationContentDescription);
  + }
  +
  @ReactProp(name = "overflowImage")
  public void setOverflowIcon(SearchToolbarView view, ReadableMap overflowIcon) {
  view.setOverflowIconSource(overflowIcon);
  