I want to set repoy back to showing only code from 4.0.3 throughout the codebase.
Thanks to all the help from everyone particularly buzeeg and R0MANARMY, figured it out. The tags for android are listed at https://android.googlesource.com/platform/manifest.git and the command to actually switch to that tag, provided you have it already, is repo start --all only add the --all if you want the entire source changed over. Specify a particular packagename if you want just that changed.