[Resolv][apex] Delete resolver apex files in system/netd/apex

We have moved resolver source code from system/netd/resolv/ to
packages/modules/DnsResolver/. We also delete resolver apex
files in system/netd/apex.

Bug: 134997188
Test: make; flash; check resolv apex file.
Merged-In: I087c2d130cb58c1f61aaf86f52e4822952880e1a
Change-Id: I57fb770acea07e7d7532d33a28ed5051710d52a6