[YouTube] Return approxDurationMs value from YouTube's player response in ItagItems generated

This change allows to build DASH manifests using YoutubeDashManifestCreator with the real duration of streams and prevent potential cuts of the end of progressive streams, because the duration in YouTube's player response is in seconds and not milliseconds.

Author: AudricV

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeStreamExtractor.java

@@ -20,6 +20,7 @@
 
 package org.schabi.newpipe.extractor.services.youtube.extractors;
 
+import static org.schabi.newpipe.extractor.services.youtube.ItagItem.APPROX_DURATION_MS_UNKNOWN;
 import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.CONTENT_CHECK_OK;
 import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.CPN;
 import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.RACY_CHECK_OK;
@@ -1396,9 +1397,11 @@ private void buildAndAddItagInfoToList(
             itagItem.setAudioChannels(formatData.getInt("audioChannels"));
         }
 
-        // YouTube return the content length as a string
+        // YouTube return the content length and the approximate duration as strings
         itagItem.setContentLength(Long.parseLong(formatData.getString("contentLength",
                 String.valueOf(CONTENT_LENGTH_UNKNOWN))));
+        itagItem.setApproxDurationMs(Long.parseLong(formatData.getString("approxDurationMs",
+                String.valueOf(APPROX_DURATION_MS_UNKNOWN))));
 
         final ItagInfo itagInfo = new ItagInfo(streamUrl, itagItem);