There is no information shown on how long the Droid Mystery Bag would remain in the game, but it would probably be removed after 1-2 days, starting today.
You can send the Droid Mystery Bag from the Free Gifts page. There are also automated scripts out there which you can use to help send the bags, such as the Massive Sender(MWAddon) or Gift Blaster(Spockholm).
Here is the screenshot of what i received from opening 20 bags. I did not receive much points, but who can't reject free stat points?
Upon opening 20 bags for the day, the Droid Mystery Bags will automatically be converted into the Blue Mystery Bags.
The Special Loot you can receive from the Vacay Mystery Bags is the Droidian Slip (126/170). It will randomly drop when opening the bags, along with other great stuffs such as the +5 Attack, Defense, Stamina, Energy, Skill Points and Stamina Boost.