detail: add playing indicator to genre artists

Add playing indicators to artists within the genre detail view.

app/src/main/java/org/oxycblt/auxio/detail/DetailViewModel.kt

@@ -98,7 +98,6 @@ class DetailViewModel(application: Application) :
     var artistSort: Sort
         get() = settings.detailArtistSort
         set(value) {
-            logD(value)
             settings.detailArtistSort = value
             currentArtist.value?.let(::refreshArtistData)
         }
@@ -227,7 +226,7 @@ class DetailViewModel(application: Application) :
             for (entry in byDisc.entries) {
                 val disc = entry.key
                 val discSongs = entry.value
-                data.add(DiscHeader(disc)) // Ensure ID uniqueness
+                data.add(DiscHeader(disc))
                 data.addAll(discSongs)
             }
         } else {

app/src/main/java/org/oxycblt/auxio/detail/GenreDetailFragment.kt

@@ -203,11 +203,16 @@ class GenreDetailFragment :
     }
 
     private fun updatePlayback(song: Song?, parent: MusicParent?, isPlaying: Boolean) {
-        if (parent is Genre && parent == unlikelyToBeNull(detailModel.currentGenre.value)) {
-            detailAdapter.updateIndicator(song, isPlaying)
-        } else {
-            // Ignore song playback not from the genre
-            detailAdapter.updateIndicator(null, isPlaying)
+        var item: Item? = null
+
+        if (parent is Artist) {
+            item = parent
         }
+
+        if (parent is Genre && parent.uid == unlikelyToBeNull(detailModel.currentGenre.value).uid) {
+            item = song
+        }
+
+        detailAdapter.updateIndicator(item, isPlaying)
     }
 }