[fenix] Closes https://github.com/mozilla-mobile/fenix/issues/18899: Update content description string for synced tabs icon (https://github.com/mozilla-mobile/fenix/pull/18963)

app/src/main/res/layout/component_tabstray2.xml

@@ -122,7 +122,7 @@
             android:id="@+id/synced_tab_item"
             android:layout_width="0dp"
             android:layout_height="match_parent"
-            android:contentDescription="@string/tabs_header_private_tabs_title"
+            android:contentDescription="@string/tabs_header_synced_tabs_title"
             android:foregroundTint="@color/photonWhite"
             android:icon="@drawable/ic_synced_tabs" />
 

app/src/main/res/values/strings.xml

@@ -592,6 +592,8 @@
     <string name="tabs_header_private_title">Private session</string>
     <!-- Title for the list of tabs in the current private session -->
     <string name="tabs_header_private_tabs_title">Private tabs</string>
+    <!-- Title for the list of tabs in the synced tabs -->
+    <string name="tabs_header_synced_tabs_title">Synced tabs</string>
     <!-- Content description (not visible, for screen readers etc.): Add tab button. Adds a news tab when pressed -->
     <string name="add_tab">Add tab</string>
     <!-- Content description (not visible, for screen readers etc.): Add tab button. Adds a news tab when pressed -->