2 tests sometimes timing out on gcstress/debug.

Test: run-libcore-tests
Change-Id: I60ffe8104ff16563f2a68ebfe7dd63758d59bf0e
diff --git a/tools/libcore_gcstress_debug_failures.txt b/tools/libcore_gcstress_debug_failures.txt
index 5806b61..d27b8fc 100644
--- a/tools/libcore_gcstress_debug_failures.txt
+++ b/tools/libcore_gcstress_debug_failures.txt
@@ -11,9 +11,11 @@
   names: ["jsr166.CompletableFutureTest#testCompleteOnTimeout_completed",
           "libcore.icu.TransliteratorTest#testAll",
           "libcore.icu.RelativeDateTimeFormatterTest#test_bug25821045",
+          "libcore.icu.RelativeDateTimeFormatterTest#test_bug25883157",
           "libcore.java.lang.ref.ReferenceQueueTest#testRemoveWithDelayedResultAndTimeout",
           "libcore.java.lang.ref.ReferenceQueueTest#testRemoveWithDelayedResultAndNoTimeout",
           "libcore.java.util.TimeZoneTest#testSetDefaultDeadlock",
+          "libcore.javax.crypto.CipherBasicsTest#testBasicEncryption",
           "org.apache.harmony.tests.java.util.TimerTest#testThrowingTaskKillsTimerThread"]
 }
 ]