Revert "Re-enable EnableCollection/IsCollected tests"

Bug: 70958370
Bug: 69121056

This reverts commit 04f6332066858f74e62dd9eec4785582cd19495a.

Change-Id: Id8aec9fc5a269bf915bb80c3e5f929b83a7e3ea9
diff --git a/tools/prebuilt_libjdwp_art_failures.txt b/tools/prebuilt_libjdwp_art_failures.txt
index 197ca80..5251daf 100644
--- a/tools/prebuilt_libjdwp_art_failures.txt
+++ b/tools/prebuilt_libjdwp_art_failures.txt
@@ -102,9 +102,22 @@
            "org.apache.harmony.jpda.tests.jdwp.VirtualMachine.CapabilitiesNewTest#testCapabilitiesNew001" ]
 },
 {
+  description: "Test is flaky",
+  result: EXEC_FAILED,
+  bug: 69121056,
+  name: "org.apache.harmony.jpda.tests.jdwp.ObjectReference.IsCollectedTest#testIsCollected001"
+},
+{
   description: "Test for ddms extensions that are not implemented for prebuilt-libjdwp",
   result: EXEC_FAILED,
   bug: 69169846,
   name: "org.apache.harmony.jpda.tests.jdwp.DDM.DDMTest#testChunk001"
+},
+{
+  description: "Test is flakey",
+  result: EXEC_FAILED,
+  bug: 70958370,
+  names: [ "org.apache.harmony.jpda.tests.jdwp.ObjectReference.EnableCollectionTest#testEnableCollection001",
+           "org.apache.harmony.jpda.tests.jdwp.MultiSession.EnableCollectionTest#testEnableCollection001" ]
 }
 ]