Power button no longer opens interactive menu in Xenial

In gnome-shell, the hardware power button does not open the interactive power menu. It sleeps the computer instead.

The configuration backend to customize this behaviour was intentionally removed in commit [50564cde49ca2][1] (for [bug 753713][2]). After [some discussion](https://bugzilla.gnome.org/show_bug.cgi?id=755953), it's returned in [gnome-settings-daemon
3.20](https://bugzilla.gnome.org/show_bug.cgi?id=755953#c29).

Unfortunately, 3.20 is not in the [16.04 ubuntu repos](https://launchpad.net/ubuntu/+source/gnome-settings-daemon) (however there is a 3.20 release for Yakkety 16.10).

Can 3.20 be released in xenial-updates?

Removing this functionality is a disruptive change and it appears it was introduced in the Xenial LTS release (3.17 was not in Wily). While I understand gnome doesn't follow Ubuntu's stable release strategy and this is one in a large system of applications, can we get gnome-settings-daemon upgraded to 3.20 in Xenial?

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Use case scenarios for why this is disruptive:

* [Accidentally hitting the power button](https://www.reddit.com/r/gnome/comments/3oddse/buttonpower_gone_in_318/cvwd2ho) sleeps the computer without recourse. The interactive menu gives you 60 seconds to cancel.
* Laptops can already suspend when the lid is closed. While the power button can be configured to hibernate instead of sleep, my laptop does not support hibernate. Now I have a nonfunctional button (when configured to hibernate) or two ways to do the same action.
* Laptops with low battery life cannot last long in suspend state. (And again, hibernate does not always work.)
* The initial change was made to make the media buttons do what their labels say, but the "power" button no longer controls powering off the machine.

Removing "shutdown" from the list of configurations is reasonable on the grounds that it is destructive, but removing "interactive" doesn't follow since it's the least destructive. The power button was the most convenient way to invoke that menu.

Thank you for your consideration.

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Additional information:

$ lsb_release -rd
Description: Ubuntu 16.04.1 LTS
Release: 16.04

$ apt-cache policy gnome-settings-daemon
gnome-settings-daemon:
  Installed: 3.18.2-0ubuntu3
  Candidate: 3.18.2-0ubuntu3.1
  Version table:
     3.18.2-0ubuntu3.1 500
        500 http://ca.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages
 *** 3.18.2-0ubuntu3 500
        500 http://ca.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status

  [1]: https://git.gnome.org/browse/gnome-settings-daemon/commit/?id=50564cde49ca2
  [2]: https://bugzilla.gnome.org/show_bug.cgi?id=753713