Version bump to PD1A.180720.013

Change-Id: Id4722c7eec54724cf7f8af19929260c2c6c37336
diff --git a/core/build_id.mk b/core/build_id.mk
index 793d9cb..a5f5443 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=PD1A.180720.012
+export BUILD_ID=PD1A.180720.013