cc_import system_provided still sets rpath

### Description of the problem / feature request:

I have a `cc_import` with `interface_library` set and `system_provided` set to true. I'd expect a binary depending on this would show the library as `NEEDED` but not to add it to the `RUNPATH` of the binary. I'm however seeing it being added into the `RUNPATH`. Is this the intended behaviour?

Start with the cc_import handling for interface_library and system_provided, then reproduce the reported link output and inspect the generated RUNPATH and NEEDED entries. Done means establishing whether this combination is intended and, if not, identifying the relevant Bazel build-system behavior to change.

Written by the indexing model from the issue text.