deps: switch material to 1.6.0-rc01

Switch material components to the more stable 1.6.0-rc01. Have to deal
with android complaining, but whatever.

app/build.gradle

@@ -102,7 +102,7 @@ dependencies {
     implementation "io.coil-kt:coil:2.0.0-rc03"
 
     // Material
-    implementation "com.google.android.material:material:1.7.0-alpha01"
+    implementation "com.google.android.material:material:1.6.0-rc01"
 
     // LeakCanary
     debugImplementation "com.squareup.leakcanary:leakcanary-android:2.9.1"

app/src/main/java/org/oxycblt/auxio/home/HomeViewModel.kt

@@ -151,7 +151,7 @@ class HomeViewModel : ViewModel(), SettingsManager.Callback, MusicStore.Callback
 
     override fun onCleared() {
         super.onCleared()
-        musicStore.addCallback(this)
+        musicStore.removeCallback(this)
         settingsManager.removeCallback(this)
     }
 }

app/src/main/java/org/oxycblt/auxio/playback/system/PlaybackService.kt

@@ -64,6 +64,8 @@ import org.oxycblt.auxio.widgets.WidgetProvider
  * This service relies on [PlaybackStateManager.Callback] and [SettingsManager.Callback], so
  * therefore there's no need to bind to it to deliver commands.
  * @author OxygenCobalt
+ *
+ * TODO: Synchronize components in a less awful way.
  */
 class PlaybackService :
     Service(), Player.Listener, PlaybackStateManager.Callback, SettingsManager.Callback {
@@ -247,19 +249,19 @@ class PlaybackService :
     }
 
     private fun onSongChanged(song: Song?) {
-        if (song != null) {
-            logD("Setting player to ${song.rawName}")
-            player.setMediaItem(MediaItem.fromUri(song.uri))
-            player.prepare()
-            notificationComponent.updateMetadata(
-                song, playbackManager.parent, ::startForegroundOrNotify)
-            return
-        }
-
+        if (song == null) {
             // Clear if there's nothing to play.
             logD("Nothing playing, stopping playback")
             player.stop()
             stopAndSave()
+            return
+        }
+
+        logD("Loading ${song.rawName}")
+        player.setMediaItem(MediaItem.fromUri(song.uri))
+        player.prepare()
+        notificationComponent.updateMetadata(
+            song, playbackManager.parent, ::startForegroundOrNotify)
     }
 
     override fun onPlayingChanged(isPlaying: Boolean) {

app/src/main/java/org/oxycblt/auxio/settings/SettingsListFragment.kt

@@ -46,8 +46,7 @@ import org.oxycblt.auxio.util.systemBarInsetsCompat
  * The actual fragment containing the settings menu. Inherits [PreferenceFragmentCompat].
  * @author OxygenCobalt
  *
- * TODO: Add option to restore state
- * TODO: Add option to not restore state
+ * TODO: Add option to restore state TODO: Add option to not restore state
  */
 @Suppress("UNUSED")
 class SettingsListFragment : PreferenceFragmentCompat() {