[NS D01] Remove candidates that don't satisfy the request.

This is exactly equivalent to the previous version (though a bit
more expensive) but is useful for followup changes. See [NS D03]
to see a sample of how this will be used.

Bug: 113554781
Test: FrameworksNetTests
Change-Id: I39f3c248bd2f23f7b22bd89d2e1e031653fe9ddb