Make right nav button container unselectable

Container can be selected via Talkback with no visible children.
Ensure container will never be selected.

Change-Id: I09d2f0a587fe4ecc71f73bb7f8be098abfbb11d5
Fixes: 79488376
Test: manual: empty and visible a11y, rotate, IME button
diff --git a/packages/SystemUI/res/layout/menu_ime.xml b/packages/SystemUI/res/layout/menu_ime.xml
index 1be3375..9130fb4 100644
--- a/packages/SystemUI/res/layout/menu_ime.xml
+++ b/packages/SystemUI/res/layout/menu_ime.xml
@@ -19,6 +19,7 @@
     android:id="@+id/menu_container"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:importantForAccessibility="no"
     >
     <!-- Use width & height=match_parent for parent FrameLayout and buttons because they are placed
     inside a view that has a size controlled by weight. Ensure weight is large enough to support