Update spotx video adapter to set the spotx_ad_key used in DFP (#1614)

* Update spotx video adapter to set the spotx_ad_key used in DFP
targeting to the bid.adId

* Changed spotx adapter to set hb_adid through registerDefaultBidderSetting

	- Instead of setting the adid to the spotx key in the bid response itself
	we now set a key bid.spotx_ad_key on the bid and then overwrite the hb_adid
	using this key.

modules/spotxBidAdapter.js

@@ -11,6 +11,20 @@ function Spotx() {
   let bidReq;
   let KVP_Object;
 
+  const _defaultBidderSettings = {
+    alwaysUseBid: true,
+    adserverTargeting: [
+      {
+        key: 'hb_adid',
+        val: function (bidResponse) {
+          return bidResponse.spotx_ad_key;
+        }
+      }
+    ]
+  };
+
+  bidmanager.registerDefaultBidderSetting('spotx', _defaultBidderSettings);
+
   baseAdapter.callBids = function(bidRequest) {
     if (!bidRequest || !bidRequest.bids || bidRequest.bids.length === 0) {
       return;
@@ -85,7 +99,7 @@ function Spotx() {
 
       bid.cpm = KVP_Object.spotx_bid;
       bid.vastUrl = url;
-      bid.ad = url;
+      bid.spotx_ad_key = KVP_Object.spotx_ad_key;
 
       var sizes = utils.isArray(bidReq.sizes[0]) ? bidReq.sizes[0] : bidReq.sizes;
       bid.height = sizes[1];