Make this test work again with new uds implementation

Summary:
With the new uds implementation, when some data is meant to replace an old one, it has to use replace() instead of insert() to avoid an assert of data already exists.
Use 3 different entries and only insert().

Test Plan:
before: crash in the uds assert
after: passes the test

Reviewers: Dolphin, Frameworks, elvisangelaccio

Reviewed By: Dolphin, elvisangelaccio

Subscribers: bcooksley, bshah, nalvarez, cfeck, dfaure, aacid, ngraham, bruns, elvisangelaccio, kfm-devel

Tags: Dolphin

Differential Revision: https://phabricator.kde.org/D13813