Suite: Add application service interface to custom app service implementation when custom code is enabled #15058
Description
Reported at https://support.abp.io/QA/Questions/5642#answer-3a0d3862-7cf6-12ce-175c-fea81e1e0470
Checklist
- I fully tested it as developer / designer and created unit / integration tests
- I documented it (or no need to document or I will create a separate documentation issue)
- I worked with the design team to get their idea for UI/UX design (or no need to design for this PR)
- I've assigned reviewer, related labels and set a milestone for this PR