Refresh public certificates after successful pairing.

PiperOrigin-RevId: 928803074

sharing/nearby_sharing_service_impl.cc

@@ -2690,6 +2690,9 @@ void NearbySharingServiceImpl::OnPeerSyncBindingComplete(
           .set_binding_id(binding_id)
           .set_status(TransferMetadata::Status::kComplete)
           .build());
+
+  // Download public certificates again to update the newly added sync binding.
+  certificate_manager_->DownloadPublicCertificates();
 }
 
 void NearbySharingServiceImpl::OnReceivedIntroduction(

sharing/nearby_sharing_service_impl_test.cc

@@ -5219,6 +5219,8 @@ TEST_F(NearbySharingServiceImplTest, InitiatePairingSuccess) {
   EXPECT_FALSE(
       fake_nearby_connections_manager_->connection_endpoint_info(kEndpointId)
           .has_value());
+  // Once from RegisterSendSurface and once from OnPeerSyncBindingComplete.
+  EXPECT_EQ(certificate_manager()->num_download_public_certificates_calls(), 2);
 
   std::optional<nearby::sharing::sync::SyncBindingPrefs> binding =
       preference_manager_.GetSyncBindingValue();