Version bump to PPR1.180531.004

Change-Id: Ib7800424efe784be9734ab7e62061deea7f19556
diff --git a/core/build_id.mk b/core/build_id.mk
index 1755ddb..77ff428 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=PPR1.180531.003
+export BUILD_ID=PPR1.180531.004