Implement host service manager

On the host, after

  setDefaultServiceManager(createRpcDelegateServiceManager())

is called, defaultServiceManager() will return
a service manager delegate that calls into the service
manager on the device.

Test: binderHostDeviceTest with servicedispatcher installed
Bug: 190233850

Change-Id: I44f9d2e2419883e242fea0472d702f559dd0b283
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index d8f8e55..da570f3 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -151,6 +151,7 @@
                 "libbase",
             ],
             srcs: [
+                "ServiceManagerHost.cpp",
                 "UtilsHost.cpp",
             ],
         },