Skip art 121-simple-suspend-check

It is flaky on CI

Change-Id: I33c00f461d266e71c70ca7349864e59018cd1cc6

src/test/testbase/java/com/android/tools/r8/R8RunArtTestsTest.java

diff --git a/src/test/testbase/java/com/android/tools/r8/R8RunArtTestsTest.java b/src/test/testbase/java/com/android/tools/r8/R8RunArtTestsTest.java
index d1b80fa..c1b3f3f 100644
--- a/src/test/testbase/java/com/android/tools/r8/R8RunArtTestsTest.java
+++ b/src/test/testbase/java/com/android/tools/r8/R8RunArtTestsTest.java
@@ -1116,6 +1116,9 @@
           // Produces wrong output when compiled in release mode, which we cannot express.
           .put("015-switch", TestCondition.match(TestCondition.runtimes(DexVm.Version.V4_0_4)))
           .put("074-gc-thrash", TestCondition.match(TestCondition.runtimes(DexVm.Version.V4_0_4)))
+          .put(
+              "121-simple-suspend-check",
+              TestCondition.match(TestCondition.runtimes(DexVm.Version.V4_4_4)))
           .build();
 
   public static List<String> requireInliningToBeDisabled =