BannerAdUnit ignores width and height

[ValentinPostindustria]

Describe the bug
Starts from version 2.1.7. When you create BannerAdUnit with BannerParameters, it ignores the ad size passed in the constructor.

adUnit = new BannerAdUnit(CONFIG_ID, WIDTH, HEIGHT);

BannerParameters parameters = new BannerParameters();
parameters.setApi(Arrays.asList(Signals.Api.MRAID_2, Signals.Api.OMID_1));
adUnit.setBannerParameters(parameters);

As a result, the response will be:

Invalid request format: request.imp[0].banner has no sizes. Define "w" and "h", or include "format" elements

Expected behavior
The ad size must be set up by the constructor if there is no ad sizes in BannerParameters.