vars: We now have a script for build id

TODO: Fully automate
Change-Id: Ibdcd15f24cbe6477ac84d63f019ff1f145fa2def
diff --git a/vars/crosshatch b/vars/crosshatch
index 460d280..1e92c15 100644
--- a/vars/crosshatch
+++ b/vars/crosshatch
@@ -21,7 +21,7 @@
   device/google/crosshatch
 )
 
-# Updated manually
+# Updated semi-manually via pixel/update-any-var.sh
 
 readonly prev_build_id=SP1A.210812.016.C1 # Feb 2022
 readonly build_id=SP1A.210812.016.C2 # Jun 2022