Undo unintentional reordering of Art versions

Change-Id: I8f4718c1407dd172469a2ae62356e830e0d4401a
diff --git a/src/test/java/com/android/tools/r8/ToolHelper.java b/src/test/java/com/android/tools/r8/ToolHelper.java
index 21147f8..4392339 100644
--- a/src/test/java/com/android/tools/r8/ToolHelper.java
+++ b/src/test/java/com/android/tools/r8/ToolHelper.java
@@ -337,9 +337,9 @@
       V5_1_1("5.1.1"),
       V6_0_1("6.0.1"),
       V7_0_0("7.0.0"),
+      V8_1_0("8.1.0"),
       // TODO(b/204855476): Remove DEFAULT.
       DEFAULT("default"),
-      V8_1_0("8.1.0"),
       V9_0_0("9.0.0"),
       V10_0_0("10.0.0"),
       V12_0_0("12.0.0"),