Version bump to QD1A.190821.011.C4 [core/build_id.mk]

Change-Id: I3353f6a60c82394a6f96858e3f4aa40cc6ebd1cf
diff --git a/core/build_id.mk b/core/build_id.mk
index 59f2d21..3096641 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.
 
-BUILD_ID=QD1A.190821.011.C3
+BUILD_ID=QD1A.190821.011.C4