Grid Bid Adapter: add support for video.plcmt (prebid#9763)

* Update gridBidAdapter.js

* Update gridBidAdapter_spec.js

Author: patmmccann

modules/gridBidAdapter.js

@@ -980,6 +980,7 @@ function buildCdbRequest(context, bidRequests, bidderRequest) {
           api: bidRequest.mediaTypes.video.api,
           skip: bidRequest.mediaTypes.video.skip,
           placement: bidRequest.mediaTypes.video.placement,
+          plcmt: bidRequest.mediaTypes.video.plcmt,
           minduration: bidRequest.mediaTypes.video.minduration,
           playbackmethod: bidRequest.mediaTypes.video.playbackmethod,
           startdelay: bidRequest.mediaTypes.video.startdelay

test/spec/modules/gridBidAdapter_spec.js

@@ -423,6 +423,7 @@ describe('TheMediaGrid Adapter', function () {
               api: [1, 2],
               skip: 1,
               placement: 1,
+              plcmt: 2,
               minduration: 0,
               playbackmethod: 1,
               startdelay: 0
@@ -539,6 +540,7 @@ describe('TheMediaGrid Adapter', function () {
             ],
             'minduration': 0,
             'placement': 1,
+            'plcmt': 2,
             'playbackmethod': 1,
             'playersizes': [
               '400x600'