Implement getTransport.

hwservicemanager now reads the vintf directly so that libhidl* doesn't
have to depend on libvintf.

Test: extensive, see change Ia5d1eb41b057ab5d6800f6c3fd22658adecc4be7
Bug: 36377072
Change-Id: I82593bde03fc445ce37145b01a8ee1a088d499a6
5 files changed