Make change and version bump to OPR6.170623.020

Change-Id: I46d2d8e4ed079722a594300cde20207d7e3ab88a
diff --git a/core/build_id.mk b/core/build_id.mk
index d27c48e..b76b84d 100644
--- a/core/build_id.mk
+++ b/core/build_id.mk
@@ -18,4 +18,4 @@
 # (like "CRB01").  It must be a single word, and is
 # capitalized by convention.
 
-export BUILD_ID=OPR2.170623.008
+export BUILD_ID=OPR6.170623.020