Fix: Danger xcov report won't work correctly when Constants.TESTS_SCHEME is different with PRODUCT_NAME

[markgravity]

Issue

Danger xcov report won't show Code Coverage report when Schema name is different with PRODUCT_NAME, if we use only_project_targets: true

And the solution is from @minhnimble on his PR

Expected

Danger should show Code Coverage report

Steps to reproduce

1. Create a new project from `ios-template
2. Change PRODUCT_NAME in Build Settings to make it different from the Constants.TESTS_SCHEME
3. Run bundle exec danger local