Correct the comparison done in removeAdapter.

Since addAdapter is storing the proxy binder objects in the adapter set, we need
to compare the underlying binder objects when trying to remove the adapter
from the adapter set. This was resulting in adapters accumulating in adapter
set every time a RemoteService was created.

BUG: 22062692
Change-Id: Ib9cc25a8b95622a524ed5a07d3ef56673669cd27