[fenix] Removes missing string reference

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

@@ -24,7 +24,6 @@
         android:layout_marginStart="23dp"
         android:ellipsize="none"
         android:scrollHorizontally="false"
-        android:text="@string/sessions_intro_description"
         android:textColor="@color/session_list_empty_fg"
         android:textSize="16sp"
         app:layout_constraintVertical_bias="0"

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

@@ -4,7 +4,7 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <resources>
     <!-- Name of the application -->
-    <string name="app_name">%1$s</string>
+    <string name="app_name">Fenix</string>
 
     <!-- Home Fragment -->
     <!-- Content description (not visible, for screen readers etc.): "Three dot" menu button. -->