[fenix] For https://github.com/mozilla-mobile/fenix/issues/15707: remove super.visitElement for ConstraintLayout lint.

It caused a test to fail because super.visitElement asserted false
because it expected to be overriden. It was correctly overridden - we
were just still calling through to super anyway.

mozilla-lint-rules/src/main/java/org/mozilla/fenix/lintrules/ConstraintLayoutPerfDetector.kt

@@ -168,8 +168,6 @@ class ConstraintLayoutPerfDetector : ResourceXmlDetector() {
     }
 
     override fun visitElement(context: XmlContext, element: Element) {
-        super.visitElement(context, element)
-
         // This scope is unideal: if the root element is a ConstraintLayout and is suppressed, all
         // ConstraintLayout children will also be suppressed. If more ConstraintLayout children are
         // added, the root ConstraintLayout will suppress them too. Ideally, we'd want a suppression