refactor(sabr): create FormatId for Representation directly from stream

Author: FineFindus

app/src/main/java/com/github/libretube/player/manifest/Representation.kt

@@ -10,12 +10,12 @@ import misc.Common.FormatId
 data class Representation(
     /** The format of the representation.  */
     val format: Format,
-    val itag: Int,
-    val lastModified: Long,
-    val xtags: String?,
+    /** Metadata about the stream.  */
     val stream: PipedStream,
 ) {
-    fun formatId(): FormatId =
-        FormatId.newBuilder().setItag(itag).setLastModified(lastModified).setXtags(xtags ?: "")
-            .build()
+    fun formatId(): FormatId = FormatId.newBuilder()
+        .setItag(stream.itag!!)
+        .setLastModified(stream.lastModified!!)
+        .setXtags(stream.xtags ?: "")
+        .build()
 }

app/src/main/java/com/github/libretube/player/manifest/SabrManifest.kt

@@ -101,10 +101,7 @@ class SabrManifest(
     companion object {
         private fun buildRepresentation(stream: PipedStream, format: Format) = Representation(
             format,
-            stream.itag!!,
-            stream.lastModified!!,
-            stream.xtags,
-            stream
+            stream,
         )
     }
 }