No feedback when changing Launcher's icon size

So far this is specced this way by design. I can see how this isn't exactly awesome but I'm not sure whether we should change unity8's behavior (to allow changing the launcher's size in staged mode too) or if the settings page should hint that this will work only in desktop mode.

Added ubuntu-ux to clarify

Actually this seems to mix 2 different things:

* the description says "Make sure 'Desktop mode' is switched off" in which case changes in the launcher's size would be ignored completely

* Even when in desktop mode, but having the launcher set to autohide, it would not reveal the launcher in order to give feedback.

For the former we need design input. For the latter, I would think we can just fix that unity8.

The linked branch makes the launcher hint itself when the size is changed.

Still need input from UX on whether to allow size changes in staged mode at all or not and what to do with the setting in system-settings in staged mode.

This bug was fixed in the package unity8 - 8.15+17.04.20170124-0ubuntu1

---------------
unity8 (8.15+17.04.20170124-0ubuntu1) zesty; urgency=medium

  [ Albert Astals Cid ]
  * Limit tab-focus travelling on dialogs with a fence
  * Restore focus to where it was when our ShellDialogs get unloaded
  * Update current session after changing the user
  * Add keyboard navigation for Indicators
  * a window -> the current window
  * There's no spreadDelegate_ anymore

  [ Daniel d'Andrada ]
  * Simplify DecoratedWindow
  * Remove unnecessary warning message

  [ Josh Arenson ]
  * Add a test for the session chooser icon in the greeter's sessions
    list

  [ Lukáš Tinkl ]
  * Fix keymap not being applied on the shell itself (LP: #1626435)
  * Shell dialog improvements (kbd focus, mouse eater)
  * Start searching directly as you type, w/o having to first
    focus/click the search field.
  * Add a test for the real implementation of WindowStateStorage
  * Use a four finger gesture to open the drawer, much like in u7

  [ Michael Terry ]
  * Simplify the lightdm mock to make future greeter improvements easier
    to test.
  * Add support for guest sessions in unity8-greeter.
  * Use a model for PAM prompts, supporting more possible interactions.
  * Fix grouping of autopkg output and allow optionally passing
    arguments to installed test scripts.
  * Add support for LightDM hints for manual logins and hiding normal
    users.

  [ Michael Zanetti ]
  * hint the launcher to indicate a successful size change to the user
    (LP: #1646457)
  * Improvements for the appdrawer (LP: #1648173)
  * Adjust home key to still focus the dash instead of messing with the
    drawer
  * allow 4 finger simulation with mousetouchadaptor

  [ Nick Dedekind ]
  * Added Alt+F10 shortcut to open app menus. (LP: #1656896)
  * Fixed menu layout width calculations. (LP: #1657050)
  * Skip Panel::test_drag_indicator_item_down_shows_menu

 -- Michał Sawicz <email address hidden> Tue, 24 Jan 2017 07:46:58 +0000