use dialog full screen, with set layout param, and gravity.

Dialog Full LayoutParram

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setStyle(STYLE_NO_FRAME, R.style.AppTheme);
    }

    @Override
    public void onStart() {
        super.onStart();
        ViewGroup.LayoutParams params = getDialog().getWindow().getAttributes();
        params.width = ViewGroup.LayoutParams.MATCH_PARENT;
        params.height = ViewGroup.LayoutParams.WRAP_CONTENT;
        getDialog().getWindow().setAttributes((android.view.WindowManager.LayoutParams) params);
        getDialog().getWindow().setGravity(Gravity.BOTTOM);
    }