Add API 25 to @since list.

Change-Id: I636c8e948530d4aa3900496f042f54beb57da15a
diff --git a/Android.mk b/Android.mk
index 745ce43..d813c91 100644
--- a/Android.mk
+++ b/Android.mk
@@ -860,6 +860,7 @@
     -since $(SRC_API_DIR)/22.txt 22 \
     -since $(SRC_API_DIR)/23.txt 23 \
     -since $(SRC_API_DIR)/24.txt 24 \
+    -since $(SRC_API_DIR)/25.txt 25 \
 		-werror -hide 111 -hide 113 \
 		-overview $(LOCAL_PATH)/core/java/overview.html