Fix up a11y tests for recent changes

The fix for child properties made the a11y dump for the assistant
case change. After close inspection, the new output is what the
code intends to produce, so update the expected result.

testsuite/a11y/assistant.txt

@@ -9,7 +9,7 @@ window1
   button1
     "push button"
     index: 0
-    name: Button 1
+    name: Page 1
     state: enabled focusable sensitive showing visible
     toolkit: gtk
     <AtkComponent>
@@ -24,7 +24,7 @@ window1
   button2
     "push button"
     index: 0
-    name: Button 2
+    name: Page 2
     state: enabled focusable sensitive visible
     toolkit: gtk
     <AtkComponent>
@@ -47,8 +47,6 @@ window1
     alpha: 1
     close
       "push button"
-      parent: action_area
-      index: 0
       name: Close
       state: enabled focusable sensitive
       toolkit: gtk
@@ -81,8 +79,6 @@ window1
       action 0 keybinding: <Alt>c
     last
       "push button"
-      parent: action_area
-      index: 2
       name: Finish
       state: focusable
       toolkit: gtk
@@ -98,8 +94,6 @@ window1
       action 0 keybinding: <Alt>f
     back
       "push button"
-      parent: action_area
-      index: 3
       name: Go Back
       state: enabled focusable sensitive
       toolkit: gtk
@@ -132,8 +126,6 @@ window1
       action 0 keybinding: <Alt>o
     apply
       "push button"
-      parent: action_area
-      index: 5
       name: Apply
       state: enabled focusable sensitive
       toolkit: gtk