Disable test 080-oom-fragmentation only on GSS and debug CC configurations.

- With the Generational Semi-Space (GSS) garbage collector, run-test
  080-oom-fragmentation test fails due to lack of support for
  allocations larger than 32MB even with a larger max heap size.
- With the Concurrent Collector (CC) garbage collector and debug mode,
  this run test may fail because of fragmentation caused by the region
  space's cyclic region allocation (which is enabled in debug mode).

This reverts and amends commit e0b7c8ace0c18498c56f86cd9bc205af42e11a3a.

Test: art/test/testrunner/testrunner.py -t 080-oom-fragmentation (in GSS and debug CC modes)
Bug: 33795328
Change-Id: I07e68d189e0088fb722cda4c34b020f303cb2081
diff --git a/test/knownfailures.json b/test/knownfailures.json
index f0b88e9..8ca0012 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -13,7 +13,17 @@
     },
     {
         "tests": "080-oom-fragmentation",
-        "description": "Disable 080-oom-fragmentation due to flakes.",
+        "description": ["Disable 080-oom-fragmentation for GSS GC due to lack of",
+                        "support for allocations larger than 32MB."],
+        "env_vars": {"ART_DEFAULT_GC_TYPE": "GSS"},
+        "bug": "http://b/33795328"
+    },
+    {
+        "tests": "080-oom-fragmentation",
+        "description": ["Disable 080-oom-fragmentation for CC collector in debug mode",
+                        "because of potential fragmentation caused by the region space's",
+                        "cyclic region allocation (which is enabled in debug mode)."],
+        "variant": "debug",
         "bug": "http://b/33795328"
     },
     {