Re-land "Fix invalid using decl in bionic relocation_packer"

This time with more namespace qualification.

Tested manually by building clang_x64/android_relocation_packer locally,
as the Android trybot analyze step does not think it needs to run for
this change.

Original description:

> The code was essentially doing 'using Logger::INFO' in the global
> namespace to make its 'LOG(INFO)' macros work. Unfortunately, C++ does
> not allow you to use using decls on classes like this unless you are in
> a derived class. GCC does not accept this code, and Clang was recently
> updated (LLVM r268594) to reject it as well.
> This should fix the Chromium Android ASan build with TOT Clang:

Cr-Commit-Position: refs/heads/master@{#391952}
2 files changed