Version bump to OPD3.170816.020

Change-Id: I877ae46c2fb87f5553e8cefd4d168e6e207f8d22
diff --git a/core/build_id.mk b/core/build_id.mk
index a561039..d7f5a5e 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=OPD3.170816.019
+export BUILD_ID=OPD3.170816.020