Fix assertion to test for final name

Change-Id: Icec81c1d7facc783f1907f452a3fbb1f742373f9
diff --git a/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DesugaredLibraryTestBase.java b/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DesugaredLibraryTestBase.java
index be3d54c..ee53f5d 100644
--- a/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DesugaredLibraryTestBase.java
+++ b/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DesugaredLibraryTestBase.java
@@ -151,10 +151,7 @@
       }
       if (shrink) {
         new CodeInspector(desugaredLib)
-            .forAllClasses(
-                clazz -> {
-                  assertTrue(clazz.getFinalSignatureAttribute().startsWith("j$"));
-                });
+            .forAllClasses(clazz -> assertTrue(clazz.getFinalName().startsWith("j$")));
       }
       return desugaredLib;
     } catch (Exception e) {