1 patch to two branches

hi my case is as follows I have two branches basically they are the same, except they differ from different package name(java) and namespace(cpp) due to customer request

but now I have a fix , say a patch I want to commit it to both branches

but I am lazy so I just want to do just one 'git commit' and 'git push'

so I am thinking using a githook in remote server and each commit to branch A can also commit to branch B as well

but I am not quite sure what I should use in the hook

git rebase , git merge or git cherry pick ?

seems these 3 ways all lead to the same result but I dont know which is better and why

thanks