Make change and version bump to OPR6.170623.018

Change-Id: I776f6e6bd3aedc2b7293b8cd204113ef25ced227
diff --git a/core/build_id.mk b/core/build_id.mk
index cd68ea3..bd4584d 100644
--- a/core/build_id.mk
+++ b/core/build_id.mk
@@ -30,4 +30,4 @@
 # https://docs.google.com/document/d/17eqVTxMc2do05T6qwt4eASVyxy8u3Cme4u4fVD5q0VM/view#
 #
 
-export BUILD_ID=OPR6.170623.014
+export BUILD_ID=OPR6.170623.018