Replace project_prefix used in the integration tests

[daniel-cit]

Replace project_prefix used in the integration tests.
Changed from tst to t01.

Collision of new projects with existing projects has become more frequent:

       Error: error creating project tst-p-shared-restricted-4d2b (tst-p-shared-restricted): googleapi: Error 409: Requested entity already exists, alreadyExists. If you received a 403 error, make sure you have the `roles/resourcemanager.projectCreator` permission
       
         on .terraform/modules/production.env.restricted_shared_vpc_host_project/modules/core_project_factory/main.tf line 65, in resource "google_project" "main":
         65: resource "google_project" "main" {    

[bharathkkb]

Thanks @daniel-cit please switch base to main branch and rebase

[daniel-cit]

@bharathkkb I switched base to main branch and rebased the code