Adjust acceptance tests to changes in link share menu behaviour

Now the link share menu is not automatically opened after a link share
is created, so waiting until it was opened failed in iShareTheLinkFor.

Note that the steps that interact with the link share menu take care
themselves of showing the menu if needed, so there is no need to
explicitly show it despite the change. Also, the waiting in
iShareTheLinkFor was introduced when the link share menu was changed
to automatically open after creating a link share, as that caused some
issues with the steps that opened the menu by themselves (fec8d12f).
Due to all this, now that the link share menu is again not automatically
opened the wait can be simply removed.

Signed-off-by: Greta Doci <gretadoci@gmail.com>