Ignore some extensions tests results

In previous commit cb05c17a47 I added a unit tests to a bunch of
extensions. Three of them are not passing though so make the tests non
voting: AccountAudit, CommunityVoice, CreditsSource

Bug: 65875
Bug: 65876
Bug: 65877
Change-Id: If55f0921441d14264fcc2a244df8555880a9d002