On Ubuntu Phone with readonly /etc we symlink /etc/{adjtime,localtime,timezone} to /etc/writable/, so we need to update those files instead if the original files are symlinks into /etc/writable/.
Set default polling interval on CD drives as well. The events_dfl_poll_msecs will not trigger if "block" is not a module, but built in. This will avoid udisks etc. having to poll from userspace, and provide proper ejection when the hardware eject button is pressed.