Does your script fork at some point (and might exit before the rsync job is completed)? Because then you need to use Type=forking instead of simple or oneshot, otherwise systemd will start trying to clean up child processes when the script exits.
Edit: Actually considering the time span involved Type=forking will not solve your issue because it will timeout, if this is the problem you need to change your script to not do that.
To be fair this also happened to Eagle Dynamics, developer of DCS, the other "realistic" flight sim that players take far too seriously. Except there it was a Dev that got arrested in Georgia and extradited to the US...
While unfortunate, not shipping these standard Google apps is not really an option for any Android manufacturer due to Google requirements. Including them is required if you want to use anything from the GSM, which includes things like the Play Store and everything it touches. You can technically ship a different Android distribution like Lineage or /e/, but that's not really what most people will be expecting of an "Android" phone and will narrow the viable target demographic even more than the value proposition already does.
Does your script fork at some point (and might exit before the rsync job is completed)?
Because then you need to useType=forking
instead ofsimple
oroneshot
, otherwise systemd will start trying to clean up child processes when the script exits.Edit: Actually considering the time span involved
Type=forking
will not solve your issue because it will timeout, if this is the problem you need to change your script to not do that.