ART: Blacklist test 908 for GC_STRESS

The test "measures" GC invocations and expects stable deterministic
behavior that cannot be guaranteed with a small heap.

Bug: 31684633
Test: m ART_TEST_GC_STRESS=true test-art-host
Change-Id: Id40f42e34b373643802e393fce7741eef549fb4b
diff --git a/test/Android.run-test.mk b/test/Android.run-test.mk
index a3c16e6..b140645 100644
--- a/test/Android.run-test.mk
+++ b/test/Android.run-test.mk
@@ -370,13 +370,16 @@
 # Tests that are broken with GC stress.
 # * 137-cfi needs to unwind a second forked process. We're using a primitive sleep to wait till we
 #   hope the second process got into the expected state. The slowness of gcstress makes this bad.
+# * 908-gc-start-finish expects GCs only to be run at clear points. The reduced heap size makes
+#   this non-deterministic.
 # * 961-default-iface-resolution-gen and 964-default-iface-init-genare very long tests that often
 #   will take more than the timeout to run when gcstress is enabled. This is because gcstress
 #   slows down allocations significantly which these tests do a lot.
 TEST_ART_BROKEN_GCSTRESS_RUN_TESTS := \
   137-cfi \
+  908-gc-start-finish \
   961-default-iface-resolution-gen \
-  964-default-iface-init-gen
+  964-default-iface-init-gen \  
 
 ifneq (,$(filter gcstress,$(GC_TYPES)))
   ART_TEST_KNOWN_BROKEN += $(call all-run-test-names,$(TARGET_TYPES),$(RUN_TYPES),$(PREBUILD_TYPES), \