Remove duplicated code in test_user_data

In test_user_data, there is duplicated code for creating a request.
In addition, there is an internal method which works as almost same
as the duplicated code.
This patch makes the tests use the internal method and removes the
duplicated code for cleanup.

Change-Id: Ie87cc14a3ac67bc1262de155dc0a1dcf5c5e7d9a
Merge "Remove duplicated code in test_user_data"