Ozone Bid Adapter : support for multi-size adUnits (prebid#12680)

* Update ozoneBidAdapter_spec.js

spectests updated

* Update ozoneBidAdapter.js

- fixed a bug with getFloors - we need to take the first index [0] of sizes
- changed instances of Array.isArray to isArray

* Update ozoneBidAdapter.js

* Update ozoneBidAdapter_spec.js

* Update ozoneBidAdapter.js

removed trailing space

* Update ozoneBidAdapter.js

Author: AskRupert-DM