[Catalog] Implement initializers in swift to avoid runtime crashes.
[Catalog] Implement initializers in swift to avoid runtime crashes.

Summary: Tested on device, simulator, and with Xcode 7.2.1 and Xcode 7.2.

Reviewers: #mdc_ios_owners, junius

Reviewed By: #mdc_ios_owners, junius

Projects: #material_components_ios

Differential Revision: http://codereview.cc/D549

brianjmoore/material-components-ios,Eccelor/material-components-ios,chriscox/material-components-ios,randallli/material-components-ios,samnm/material-components-ios,Eccelor/material-components-ios,willlarche/material-components-ios,sigito/material-components-ios,brianjmoore/material-components-ios,chriscox/material-components-ios,material-components/material-components-ios,samnm/material-components-ios,material-components/material-components-ios,Eccelor/material-components-ios,Eccelor/material-components-ios,randallli/material-components-ios,material-components/material-components-ios,sigito/material-components-ios,material-components/material-components-ios,willlarche/material-components-ios,samnm/material-components-ios,samnm/material-components-ios,brianjmoore/material-components-ios,samnm/material-components-ios,chriscox/material-components-ios,willlarche/material-components-ios,brianjmoore/material-components-ios,chriscox/material-components-ios,brianjmoore/material-components-ios,randallli/material-components-ios,Eccelor/material-components-ios,sigito/material-components-ios,willlarche/material-components-ios,chriscox/material-components-ios,randallli/material-components-ios,randallli/material-components-ios,sigito/material-components-ios,willlarche/material-components-ios,randallli/material-components-ios,material-components/material-components-ios,sigito/material-components-ios