Just using 4.x instead of 3.x

Author: fulopattila122

build-tools/README.md

@@ -3,11 +3,11 @@
 ## Release Checklist
 
 - Modify Changelog and manifest entries
-- Commit as `Release v3.x.y` (DO NOT TAG IT!)
+- Commit as `Release v4.x.y` (DO NOT TAG IT!)
 - Push to master
 - Run `build-tools/split.sh`
 - When not all the modules will be released, then change line 52 in `release.sh` temporarily 
   so that it only contain the changed modules that will be released. Otherwise, unchanged
   modules will get the tag as well, i.e. the previously released commit will have the
   previous tag and the new tag as well
-- Run `build-tools/release.sh 3.x.y`
+- Run `build-tools/release.sh 4.x.y`