Enable Java 1.8 language features in stubs

Bug: 26753820
(cherry-picked from commit 0f151d8043413429a9ce3b6139d7d93b2816cd86)

Change-Id: I5c988874c2ad9e98389f8a66691fb3545211443e
diff --git a/build/build_android_stubs.mk b/build/build_android_stubs.mk
index cea8a8d..d5b1298 100644
--- a/build/build_android_stubs.mk
+++ b/build/build_android_stubs.mk
@@ -37,7 +37,7 @@
 	$(hide) mkdir -p $(PRIVATE_CLASS_INTERMEDIATES_DIR)
 	$(hide) find $(PRIVATE_SRC_DIR) -name "*.java" > \
         $(PRIVATE_INTERMEDIATES_DIR)/java-source-list
-	$(hide) $(TARGET_JAVAC) -source 1.7 -target 1.7 -encoding ascii -bootclasspath "" \
+	$(hide) $(TARGET_JAVAC) -source 1.8 -target 1.8 -encoding ascii -bootclasspath "" \
 			-g $(xlint_unchecked) \
 			-extdirs "" -d $(PRIVATE_CLASS_INTERMEDIATES_DIR) \
 			\@$(PRIVATE_INTERMEDIATES_DIR)/java-source-list \
@@ -67,7 +67,7 @@
 	$(hide) find $(PRIVATE_SRC_DIR) -name "*.java" > \
 		$(PRIVATE_INTERMEDIATES_DIR)/jack-rsc.java-source-list
 	$(call call-jack) \
-		-D jack.java.source.version=1.7 \
+		-D jack.java.source.version=1.8 \
 		--import-resource $(PRIVATE_INTERMEDIATES_DIR)/jack-rsc.tmp \
 		--output-jack $@ \
 		@$(PRIVATE_INTERMEDIATES_DIR)/jack-rsc.java-source-list \