Enable CC (ART_USE_READ_BARRIER) by default.

Bug: 34084559
Bug: 12687968
Test: boot on angler
Test: test-art-host
Change-Id: I0287b813335b472dd59aa6b94aeeab2da60b9c99
diff --git a/test/run-test b/test/run-test
index a913e78..9b17802 100755
--- a/test/run-test
+++ b/test/run-test
@@ -722,7 +722,7 @@
     #
     # TODO: Enable Checker when read barrier support is added to more
     # architectures (b/12687968).
-    if [ "x$ART_USE_READ_BARRIER" = xtrue ]                    \
+    if [ "x$ART_USE_READ_BARRIER" != xfalse ]                  \
        && (([ "x$host_mode" = "xyes" ]                         \
             && ! arch_supports_read_barrier "$host_arch_name") \
            || ([ "x$target_mode" = "xyes" ]                    \