Fix toolbar scuba regressions

Also add findMenuItemById() and requireMenuItemById().

Also set content descriptions on MenuItems, for scuba tests / accessability.

Fixes: 144945668
Test: Manually, scuba
Change-Id: I90f08ff193c5fcc57600731563065afd109b8385
diff --git a/car-ui-lib/tests/robotests/src/com/android/car/ui/toolbar/ToolbarTest.java b/car-ui-lib/tests/robotests/src/com/android/car/ui/toolbar/ToolbarTest.java
index 68c37d1..239caee 100644
--- a/car-ui-lib/tests/robotests/src/com/android/car/ui/toolbar/ToolbarTest.java
+++ b/car-ui-lib/tests/robotests/src/com/android/car/ui/toolbar/ToolbarTest.java
@@ -332,7 +332,7 @@
 
     @Test
     public void menuItems_whenClicked_shouldCallListener() {
-        assertThat(getMenuItemViewCount()).isEqualTo(0);
+        assertThat(getMenuItemCount()).isEqualTo(0);
 
         Mutable<Boolean> button1Clicked = new Mutable<>(false);
         Mutable<Boolean> button2Clicked = new Mutable<>(false);
@@ -340,7 +340,7 @@
                 createMenuItem(i -> button1Clicked.value = true),
                 createMenuItem(i -> button2Clicked.value = true)));
 
-        assertThat(getMenuItemViewCount()).isEqualTo(2);
+        assertThat(getMenuItemCount()).isEqualTo(2);
 
         getMenuItemView(0).performClick();
 
@@ -359,11 +359,11 @@
                 createMenuItem(i -> {
                 })));
 
-        assertThat(getMenuItemViewCount()).isEqualTo(2);
+        assertThat(getMenuItemCount()).isEqualTo(2);
 
         mToolbar.setMenuItems(null);
 
-        assertThat(getMenuItemViewCount()).isEqualTo(0);
+        assertThat(getMenuItemCount()).isEqualTo(0);
     }
 
     @Test
@@ -405,7 +405,7 @@
                 }));
         mToolbar.setMenuItems(menuItems);
 
-        assertThat(getMenuItemViewCount()).isEqualTo(2);
+        assertThat(getMenuItemCount()).isEqualTo(2);
 
         View firstMenuItemView = getMenuItemView(0);
 
@@ -457,10 +457,8 @@
         when(mContext.getResources()).thenReturn(mResources);
     }
 
-    private int getMenuItemViewCount() {
-        return ((ViewGroup) mToolbar
-                .findViewById(R.id.car_ui_toolbar_menu_items_container))
-                .getChildCount();
+    private int getMenuItemCount() {
+        return mToolbar.getMenuItems().size();
     }
 
     private View getMenuItemView(int index) {