Pass app and device fields to Prebid server (#2044)

* Pass app to Prebid server

pbsrequest.go code is indeed developed to read the app fields present in the root of PBSRequest json not in the PBSRequest.ad_units child object. So far no app bundle is passed in the prebid server payload to the differents bidders...
With this fix, the device and app should be passed in the setConfig rather than AdUnits.

* Update prebidServerBidAdapter.js

modules/prebidServerBidAdapter.js

@@ -210,6 +210,8 @@ export function PrebidServer() {
   /* Prebid executes this function when the page asks to send out bid requests */
   baseAdapter.callBids = function(s2sBidRequest, bidRequests, addBidResponse, done, ajax) {
     const isDebug = !!getConfig('debug');
+    const app = !!getConfig('app');
+    const device = !!getConfig('device');
     const adUnits = utils.deepClone(s2sBidRequest.ad_units);
     adUnits.forEach(adUnit => {
       let videoMediaType = utils.deepAccess(adUnit, 'mediaTypes.video');
@@ -232,7 +234,9 @@ export function PrebidServer() {
       url: utils.getTopWindowUrl(),
       prebid_version: '$prebid.version$',
       ad_units: adUnits.filter(hasSizes),
-      is_debug: isDebug
+      is_debug: isDebug,
+      device: device,
+      app: app
     };
 
     let digiTrust = _getDigiTrustQueryParams();