Focus the SaveUi-Yes-Button by default

This is arguagble the right focus anyway. Also this prevents the close
button to be highlighted which looks rather unpleasant.

Change-Id: Id0c79babcf928b11f5db888a9d41bfd717afa5be
Fixes: 37566617
Test: looked at SaveUi

core/res/res/layout/autofill_save.xml

@@ -94,6 +94,7 @@
                 android:layout_height="wrap_content"
                 style="@style/Widget.Material.Button.Colored"
                 android:text="@string/autofill_save_yes">
+                <requestFocus />
             </Button>
 
         </com.android.internal.widget.ButtonBarLayout>