Re-enable EnableCollection/IsCollected tests

Rationale:
A few refinements have hopefully removed the flakiness.
Repeating the following three tests came out clean.

Test: org.apache.harmony.jpda.tests.jdwp.MultiSession.EnableCollectionTest
Test: org.apache.harmony.jpda.tests.jdwp.ObjectReference.EnableCollectionTest
Test: org.apache.harmony.jpda.tests.jdwp.ObjectReference.IsCollectedTest

Bug: 70958370
Bug: 69121056
Change-Id: Ic7230c521464a085bdaec242c8cde507a3e83d1d
diff --git a/tools/external_oj_libjdwp_art_failures.txt b/tools/external_oj_libjdwp_art_failures.txt
index ba764df..6c2206f 100644
--- a/tools/external_oj_libjdwp_art_failures.txt
+++ b/tools/external_oj_libjdwp_art_failures.txt
@@ -53,19 +53,6 @@
            "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 is flaky",
-  result: EXEC_FAILED,
-  bug: 70958370,
-  names: [ "org.apache.harmony.jpda.tests.jdwp.ObjectReference.EnableCollectionTest#testEnableCollection001",
-           "org.apache.harmony.jpda.tests.jdwp.MultiSession.EnableCollectionTest#testEnableCollection001" ]
-},
-{
   description: "Test times out on fugu-debug",
   result: EXEC_FAILED,
   bug: 70459916,
diff --git a/tools/prebuilt_libjdwp_art_failures.txt b/tools/prebuilt_libjdwp_art_failures.txt
index 5251daf..2664560 100644
--- a/tools/prebuilt_libjdwp_art_failures.txt
+++ b/tools/prebuilt_libjdwp_art_failures.txt
@@ -102,22 +102,9 @@
            "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" ]
-}
 ]