Remove Debug configuration in MobileSdkPassThrough

[ValentinPostindustria]

We made a separation for creating MobileSdkPassThrough, because PS didn't support this feature.

            JSONObject rootJsonObject;
            if (!BuildConfig.DEBUG) {
                if (extJson.has("prebid")) {
                    rootJsonObject = extJson.getJSONObject("prebid");
                } else return null;
            } else {
                rootJsonObject = extJson;
            }

Now it supports. So we can remove this check. Change stored impressions. And remove BuildConfig.DEBUG checker in unit tests (MobileSdkPassThroughTest).