Version bump to PD1A.180720.027

Change-Id: I657955a5797e320c8654110ee68134ea1aea7388
diff --git a/core/build_id.mk b/core/build_id.mk
index e4001c6..9b13712 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.180720.026
+export BUILD_ID=PD1A.180720.027