Enable ServiceManager APIs without servicemanager process

In some devices, like Microdroid, there is no servicemanager process.
These ServiceManager APIs may still be used with the new Accessor
pattern for communication over sockets with binder RPC.

This CL adds support for all of the getService APIs whithout relying on
the servicemanager process.

Future API support will be added separately.

Test: atest vm_accessor_test binderLibTest
Bug: 358427181
Change-Id: Ibef52415bf1509cdcd6c9cb65dbb8e20ec08d007