tp-spec 0.21.2 clarified that MessagePartSupportFlags, SupportedContentTypes and DeliveryReportingSupport are immutable. As such, they should be in NewChannels. Due to Bug #30949, DeliveryReportingSupport won't work reliably until we depend on telepathy-glib 0.13.3, so the tests shouldn't test its value, only that it exists (unless its value would be 0 anyway).
Fixed in git.
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