Convert libart-gtest to Android.bp

Change-Id: Ibea17e3e002e6ad3f82158cd3c69d087fa9b15c9
diff --git a/Android.bp b/Android.bp
index f7e909d..e8b608e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -33,6 +33,7 @@
     "profman",
     "runtime",
     "sigchainlib",
+    "test",
     "tools/cpp-define-generator",
     "tools/dmtracedump",
 ]