app: start service on draw-time

Recently, Android 14 seemed to have finally made it impossible to start
services in onStart. I never realized this error since I thought
onStart signified the beginning of the foreground state, when it was
actually onResume. I think it only worked prior due to race conditions.
Try to fix it by moving the service starting code to onResume.

See #608.

app/src/main/java/org/oxycblt/auxio/MainActivity.kt

@@ -68,8 +68,8 @@ class MainActivity : AppCompatActivity() {
         logD("Activity created")
     }
 
-    override fun onStart() {
-        super.onStart()
+    override fun onResume() {
+        super.onResume()
 
         startService(Intent(this, IndexerService::class.java))
         startService(Intent(this, PlaybackService::class.java))