Add commons-lang for now until tests are converted to lang3 (#12871)

Change-Id: I14509d95dd2e042f830a7fca6925e012483bb36d

uitest/ivy.xml

@@ -84,6 +84,10 @@
             conf="build,ide -> default" />
         <dependency org="com.vaadin" name="vaadin-testbench"
             rev="3.1.1" conf="build-provided,ide -> default" />
+        <!-- This should be removed once tests have been updated to use lang3 -->
+        <dependency org="commons-lang" name="commons-lang"
+            rev="2.6" conf="build,ide -> default" />
+
     </dependencies>
 
 </ivy-module>