Activity preset is not usable

[jmcollin78]

With the activity preset you can:

1. change preset depending on the movement sensor,
2. If a movement is detected for a certain delay, the VTherm switch to a preset (let's says Boost),
3. when the movement is no more detected for the same delay, the VTherm switch to another preset (let's says Eco)

But because the delay on and off are the same it is not usable.
We need a short "on delay" to turn on the activity mode rapidly and a longer "off delay" to avoid too much switching.

The "off delay" should be sufficiently long to wait for a new detection before switching to "off".