Move variable to super Extractor classes.

Author: FireMasterK

extractor/src/main/java/org/schabi/newpipe/extractor/channel/ChannelExtractor.java

@@ -28,6 +28,8 @@
 
 public abstract class ChannelExtractor extends ListExtractor<StreamInfoItem> {
 
+    public static final long UNKNOWN_SUBSCRIBER_COUNT = -1;
+
     public ChannelExtractor(StreamingService service, ListLinkHandler linkHandler) {
         super(service, linkHandler);
     }

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

@@ -61,8 +61,6 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
     private JsonObject initialData;
     private JsonObject videoTab;
 
-    private static final long UNKNOWN_SUBSCRIBER_COUNT = -1;
-
     /**
      * Some channels have response redirects and the only way to reliably get the id is by saving it.
      * <p>

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

@@ -103,8 +103,6 @@ public static class DeobfuscateException extends ParsingException {
     @Nullable
     private List<SubtitlesStream> subtitles = null;
 
-    private static final long UNKNOWN_SUBSCRIBER_COUNT = -1;
-
     public YoutubeStreamExtractor(final StreamingService service, final LinkHandler linkHandler) {
         super(service, linkHandler);
     }

extractor/src/main/java/org/schabi/newpipe/extractor/stream/StreamExtractor.java

@@ -47,6 +47,7 @@
 public abstract class StreamExtractor extends Extractor {
 
     public static final int NO_AGE_LIMIT = 0;
+    public static final long UNKNOWN_SUBSCRIBER_COUNT = -1;
 
     public StreamExtractor(StreamingService service, LinkHandler linkHandler) {
         super(service, linkHandler);