vulkan-cereal: fix mismatch between context ids and resource ids

We should look up based on context id.

BUG=213395171
TEST=compile

Change-Id: I3e95b1c61bc09ae2f85360148c218a5c58bb45ba
diff --git a/stream-servers/virtio-gpu-gfxstream-renderer.cpp b/stream-servers/virtio-gpu-gfxstream-renderer.cpp
index df96d28..c389a4f 100644
--- a/stream-servers/virtio-gpu-gfxstream-renderer.cpp
+++ b/stream-servers/virtio-gpu-gfxstream-renderer.cpp
@@ -1360,7 +1360,7 @@
             mResourceContexts[resId] = ids;
         } else {
             auto& ids = contextsIt->second;
-            auto idIt = std::find(ids.begin(), ids.end(), resId);
+            auto idIt = std::find(ids.begin(), ids.end(), ctxId);
             if (idIt == ids.end())
                 ids.push_back(ctxId);
         }