Hide non-bridged/bridged namespaces behind NativeLoaderNamespace class

NativeLoaderNamespace fully abstracts the non-bridged (so called
android-) and bridged namespaces.

Bug: 130388701
Test: build & pass presubmit tests
Change-Id: I3d5ca7515711e7638f4a5ab4d3a150185c3d17ac
5 files changed