ART: Add Agent Thread API

Add support for RunAgentThread. Add test.

Bug: 31684593
Test: m test-art-host-run-test-931-agent-thread
Change-Id: I5deb213fb06eedc5ee78a340458cf0dff615d0ac
diff --git a/test/Android.run-test.mk b/test/Android.run-test.mk
index 38b88e4..c8e2185 100644
--- a/test/Android.run-test.mk
+++ b/test/Android.run-test.mk
@@ -310,6 +310,7 @@
   928-jni-table \
   929-search \
   930-hello-retransform \
+  931-agent-thread \
 
 ifneq (,$(filter target,$(TARGET_TYPES)))
   ART_TEST_KNOWN_BROKEN += $(call all-run-test-names,target,$(RUN_TYPES),$(PREBUILD_TYPES), \