Disable multi-samples on TestSeedWidget

This disables multi-sampling on the TestSeedWidget test which
allows it to pass on machines that support multi-sampling.

Change-Id: I113b4f86699b3dc8a1a24c5d9038f92a1410c65d
Merge topic 'disable-test-seed-widget-multisamples' into master

e531e773 Disable multi-samples on TestSeedWidget