1. 日期可以不显示“年月日”的单位？ 2.可以设置整个dialog的背景吗？

1. 日期可以不显示“年月日”的单位？ 2.可以设置整个dialog的背景资源吗？ 3. 可以自定义标题区域，内容区域的高度吗？ 4.标题栏底部是否可以设置黑色分割线

The issue requests four picker-dialog customizations: hiding date-unit labels, setting the dialog background, customizing title and content heights, and adding a black divider below the title bar. No files, tests, or entry points are named, so begin by locating the dialog and date-picker APIs, then verify each requested option in the Android UI.

Written by the indexing model from the issue text.