Disable chime vibrations when charging

[dav23r]

This proposes to disable chimes when the watch is put on charging station.

Prior adjacent discussions:

• Turn off vibrations while charging #446 discusses more general proposition of disabling any vibrations during charging, considering drawbacks and compromise solutions.
• Customize vibrations on hour and half hour (avoid nights/weekends) #1440 proposed designating fixed time periods when chimes should be off. This was tied to implementing automatic sleep mode feature, which serves as a more general solution for stopping disturbing notification during non-active hours.
• There is also Different vibration pattern for chimes #2055 - which proposes differing vibration pattern for chimes than other notifications.

I think there's a stronger case for disabling chimes for this setting, because:

• The need to get closer to the watch to peek on the notification (if one is at distance from charging station) just to see if it's a chime or content notification adds to confusion, instead of keeping the notifications perceptible in alternative arguments laid out in Code cleanup #466
• The watch can be put at rest on charging station not necessarily at night time as in Customize vibrations on hour and half hour (avoid nights/weekends) #1440 , so this doesn't cover this fully. And even if Different vibration pattern for chimes #2055 makes chimes distinguishable from other notification at distance too - it still adds to the clutter of vibrations, when one might take the watch off just to set timing vibrations off.
• Periodic chimes are seemingly a feature that's more apt when tied to having watch on the wrist - this is somewhat personal opinion, but I look at it as a way to be mindful of time passage during work and would prefer to having the periodic vibration once I put the watch on, kinda tying it to be in working/city/time-sensitive mode. With this latter reasoning, one might consider tying vibration to 'on hand' state (if any implemented/exposed) of the watch, but that might be a digression from the proposed approach above, for now.