Garmin Connect is an application for Garmin watches, so the Samsung watch would have to implement Garmin communication protocols, or vice versa Garmin Connect would have to implement Samsnung protocols. None of it is ever likely to happen, since Garmin and Samsung are direct competitors.
You can still (probably) export actvities from the Samsung watch (or from their app) in a compatible format (FIT, GPX, or TCX), and import them into Garmin Connect manually.
I would like to connect my galaxy 3 watch to my Garmin Connect mobile app. This way I can track my heart rate no matter which watch I use. Yes, I do have a Garmin watch.
You could broadcast the HR from your Galaxy watch, and record the activity with the Garmin watch using the HR from Galaxy. Or even better, if you are not satisfied with the HR accuracy of your Garmin watch, buy HRM chest strap. It is way more accurate than any watch ever can be.
