[Catalog][TopAppBar][a11y] Fix toolbar close button not having a content description

PiperOrigin-RevId: 678362412

Author: leticiarossi

catalog/java/io/material/catalog/topappbar/TopAppBarToolbarDemoFragment.java

@@ -84,6 +84,7 @@ public boolean onOptionsItemSelected(@NonNull MenuItem menuItem) {
 
   private void initToolbar(View view, MaterialToolbar toolbar) {
     toolbar.setNavigationIcon(NAVIGATION_ICON_RES_ID);
+    toolbar.setNavigationContentDescription(R.string.cat_topappbar_close_button);
     toolbar.setNavigationOnClickListener(
         v -> showSnackbar(view, toolbar.getSubtitle() + " " + toolbar.getTitle()));
     toolbar.inflateMenu(MENU_RES_ID);

catalog/java/io/material/catalog/topappbar/res/values/strings.xml

@@ -88,6 +88,8 @@
   <string name="cat_topappbar_configure_centered">Centered</string>
   <!-- Label for a check box for configuring toolbar navigation icon [CHAR_LIMIT=NONE] -->
   <string name="cat_topappbar_configure_navigation_icon">Navigation Icon</string>
+  <!-- Label for the toolbar navigation icon when it's a close button -->
+  <string name="cat_topappbar_close_button" description="The title of the close button of the toolbar. [CHAR_LIMIT=NONE]">Close</string>
   <!-- Label for a check box for configuring toolbar menu items [CHAR_LIMIT=NONE] -->
   <string name="cat_topappbar_configure_menu_items">Menu Items</string>
   <!-- Label for a button to apply toolbar configurations [CHAR_LIMIT=NONE] -->