Store HLS trackname in the Variant class instead of Format class

library/src/main/java/com/google/android/exoplayer/hls/Variant.java

@@ -26,16 +26,13 @@ public final class Variant implements FormatWrapper {
 
   public final String url;
   public final Format format;
+  public final String name;
 
   public Variant(int index, String name, String url, int bitrate, String codecs, int width, int height) {
     this.url = url;
-    if (name != null) {
-      format = new Format(name, MimeTypes.APPLICATION_M3U8, width, height, -1, -1,
-              -1, bitrate, null, codecs);
-    } else {
-      format = new Format(Integer.toString(index), MimeTypes.APPLICATION_M3U8, width, height, -1, -1,
-              -1, bitrate, null, codecs);
-    }
+    this.name = name;
+    format = new Format(Integer.toString(index), MimeTypes.APPLICATION_M3U8, width, height, -1, -1,
+            -1, bitrate, null, codecs);
   }
 
   @Override
@@ -43,4 +40,8 @@ public final class Variant implements FormatWrapper {
     return format;
   }
 
+  public String getName() {
+    return name;
+  }
+
 }