Fix Gitaly duration timings for ApplyBfgObjectMapStreamRequest

Previously the `gitaly_duration_s` log timings only accounted for the
initial request/response time. We now measure the total time it takes to
consume the streaming response for this RPC to complete.

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/30334

lib/gitlab/gitaly_client/cleanup_service.rb

@@ -13,15 +13,15 @@ module Gitlab
       end
 
       def apply_bfg_object_map_stream(io, &blk)
-        responses = GitalyClient.call(
+        GitalyClient.streaming_call(
           storage,
           :cleanup_service,
           :apply_bfg_object_map_stream,
           build_object_map_enum(io),
           timeout: GitalyClient.long_timeout
-        )
-
-        responses.each(&blk)
+        ) do |response|
+          response.each(&blk)
+        end
       end
 
       private

spec/lib/gitlab/gitaly_client/cleanup_service_spec.rb

@@ -22,5 +22,11 @@ describe Gitlab::GitalyClient::CleanupService do
 
       client.apply_bfg_object_map_stream(StringIO.new)
     end
+
+    it 'is wrapped as a streaming call' do
+      expect(Gitlab::GitalyClient).to receive(:streaming_call).with(anything, :cleanup_service, :apply_bfg_object_map_stream, anything, anything)
+
+      client.apply_bfg_object_map_stream(StringIO.new)
+    end
   end
 end