Update test expectations for implicit null check test

Change-Id: I3e4763ac70eb4ed72c2a81042971345bec5b38eb
diff --git a/src/test/java/com/android/tools/r8/R8RunArtTestsTest.java b/src/test/java/com/android/tools/r8/R8RunArtTestsTest.java
index 4f8c1fa..afb440a 100644
--- a/src/test/java/com/android/tools/r8/R8RunArtTestsTest.java
+++ b/src/test/java/com/android/tools/r8/R8RunArtTestsTest.java
@@ -695,6 +695,7 @@
           .put("551-implicit-null-checks",
               TestCondition.match(
                   TestCondition.tools(DexTool.NONE, DexTool.DX),
+                  TestCondition.compilers(CompilerUnderTest.R8_AFTER_D8),
                   TestCondition.runtimes(DexVm.Version.V5_1_1)))
           // Contains a method (B.<init>) which pass too few arguments to invoke. Also, contains an
           // iput on a static field.