Fix expectation in test

Dalvik VMs give a NullPointerException when enums are stripped with R8.

Bug:
Change-Id: I43d15feb0441360c89079e58084a1bd8b64146c8
diff --git a/src/test/java/com/android/tools/r8/naming/EnumMinification.java b/src/test/java/com/android/tools/r8/naming/EnumMinification.java
index 3f6e4e7..a8708eb 100644
--- a/src/test/java/com/android/tools/r8/naming/EnumMinification.java
+++ b/src/test/java/com/android/tools/r8/naming/EnumMinification.java
@@ -11,6 +11,7 @@
 import com.android.tools.r8.R8Command;
 import com.android.tools.r8.TestBase;
 import com.android.tools.r8.ToolHelper;
+import com.android.tools.r8.ToolHelper.DexVm;
 import com.android.tools.r8.ToolHelper.ProcessResult;
 import com.android.tools.r8.origin.Origin;
 import com.android.tools.r8.utils.AndroidApp;
@@ -55,7 +56,9 @@
         result.stderr,
         containsString(
             backend == Backend.DEX
-                ? "java.lang.NoSuchMethodException"
+                ? ToolHelper.getDexVm().isNewerThan(DexVm.ART_4_4_4_HOST)
+                    ? "java.lang.NoSuchMethodException"
+                    : "java.lang.NullPointerException"
                 : "java.lang.IllegalArgumentException"));
   }
 }