Fix jsr166-tests for aosp buildbots

Change-Id: I1135d8589cd0ba13dae5457c93991642cda7ce71
diff --git a/JavaLibrary.mk b/JavaLibrary.mk
index 756ec02..c9f2bc4 100644
--- a/JavaLibrary.mk
+++ b/JavaLibrary.mk
@@ -218,6 +218,7 @@
 LOCAL_JAVA_LIBRARIES := core-oj core-libart core-lambda-stubs core-junit
 LOCAL_JAVACFLAGS := $(local_javac_flags)
 LOCAL_MODULE := jsr166-tests
+LOCAL_JAVA_LANGUAGE_VERSION := 1.8
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/JavaLibrary.mk
 include $(BUILD_STATIC_JAVA_LIBRARY)
 endif