Use libc++ versions of gtest libs when needed

Change-Id: I19aa58a83a9da680d441af5f3956a2fbdf18c4e4
diff --git a/core/host_test_internal.mk b/core/host_test_internal.mk
index 650b9c6..c2c3186 100644
--- a/core/host_test_internal.mk
+++ b/core/host_test_internal.mk
@@ -5,7 +5,11 @@
 LOCAL_CFLAGS += -DGTEST_OS_LINUX -DGTEST_HAS_STD_STRING -O0 -g
 LOCAL_C_INCLUDES +=  external/gtest/include
 
+ifneq ($(filter libc++,$(LOCAL_SHARED_LIBRARIES)),)
+LOCAL_STATIC_LIBRARIES += libgtest_libcxx_host libgtest_main_libcxx_host
+else
 LOCAL_STATIC_LIBRARIES += libgtest_host libgtest_main_host
 LOCAL_SHARED_LIBRARIES +=
+endif
 
 LOCAL_LDLIBS += -lpthread