[bazel] Add mdc_snapshot_swift_library. (#8680)
[bazel] Add mdc_snapshot_swift_library. (#8680)

This is being added to support Snapshot swift tests in https://github.com/material-components/material-components-ios/pull/8679

Part of https://github.com/material-components/material-components-ios/issues/8644
material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios