Revert changes to SingleReqView and MultiReqView

src/ruby/lib/grpc/generic/active_call.rb

@@ -454,14 +454,12 @@ module GRPC
     # SingleReqView limits access to an ActiveCall's methods for use in server
     # handlers that receive just one request.
     SingleReqView = view_class(:cancelled, :deadline, :metadata,
-                               :output_metadata, :peer, :peer_cert,
-                               :trailing_metadata)
+                               :output_metadata, :peer, :peer_cert)
 
     # MultiReqView limits access to an ActiveCall's methods for use in
     # server client_streamer handlers.
     MultiReqView = view_class(:cancelled, :deadline, :each_queued_msg,
-                              :each_remote_read, :metadata, :output_metadata,
-                              :trailing_metadata)
+                              :each_remote_read, :metadata, :output_metadata)
 
     # Operation limits access to an ActiveCall's methods for use as
     # a Operation on the client.