Fix first item not a11y focusable in SimListDialog

The root cause is there is a logic to get LayoutParams from parent, but
set to child, which cause some chaos.

This dialog can be started with
`adb shell am start -n com.android.settings/.sim.SimDialogActivity --ei
dialog_type 0`

Bug: 227418839
Test: manual test when Talkback enabled
Change-Id: Ia1014dea49cb5cf372afe5bb50972277309c7f63

res/layout/sim_confirm_dialog_multiple_enabled_profiles_supported.xml

@@ -38,6 +38,8 @@
             android:background="@drawable/sim_confirm_dialog_rounded_bg"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:layout_marginTop="@dimen/sims_select_margin_top"
+            android:layout_marginBottom="@dimen/sims_select_margin_bottom"
             android:visibility="gone"/>
 
         <LinearLayout