1、设置background为透明

	<style name="BottomSheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
        <item name="bottomSheetStyle">@style/bottomSheetStyleWrapper</item>
    </style>
    <style name="bottomSheetStyleWrapper" parent="Widget.Design.BottomSheet.Modal">
        <item name="android:background">@android:color/transparent</item>
    </style>

2、应用样式

dialog_take_pic.xml最外层布局(LinearLayout)加上圆角样式代码：

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <corners
        android:topLeftRadius="5dp"
        android:topRightRadius="5dp" />
    <solid android:color="@color/white" />
</shape>