Don't rely on a black list of codecs for the serialization
test. This breaks badly when new codecs get added to Qt
(e.g. through ICU). Instead use a white list of known
codecs that can encode/decode the test data.
Change-Id: I1dc55a25e852198bb935f070a4a21e8369f56268
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>