This reverts #116200
We changed the polling logic to avoid polling if all chars are marked as watchable
to avoid crashing the firmware on a very limited set of devices as it was
more in line with what iOS does. In the end, the user ended up replacing
the device in #116143 because it turned out to be unreliable in other
ways. The vendor has since issued a firmware update that may resolve
the problem with all of these devices.
In practice it turns out many more devices
report that chars are evented and never send events. After a few months
of data and reports the trade-off does not seem worth it since
users are having to set up manual polling on a wide range of
devices. The amount of devices with evented chars that do not
actually send state vastly exceeds the number of devices that
might crash if they are polled too often so restore the previous
behavior
fixes#138561fixes#100331fixes#124529fixes#123456fixes#130763fixes#124099fixes#124916fixes#135434fixes#125273fixes#124099fixes#119617
