The internal version number (which is different than the version number you can set for convenience) will automatically be incremented for you when you rebuild the app. That is what is needed for the update to be accepted.
My answer was intended to build on the one given by anteos, hoping to clarify what does need to change.
However, it can be useful to change the package name (from com to net) if you want to have 2 different versions with mostly the same features (like free and paid), and they will be treated as 2 separate apps.
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However, it can be useful to change the package name (from com to net) if you want to have 2 different versions with mostly the same features (like free and paid), and they will be treated as 2 separate apps.