playback: fix vertical scrolling interception

Fix an issue where the cover ViewPager would intercept vertical swipes
to collapse the queue sheet. This required manually configuring nested
scrolling states in the the internal RecyclerView.

app/src/main/java/org/oxycblt/auxio/playback/PlaybackPanelFragment.kt

@@ -107,6 +107,8 @@ class PlaybackPanelFragment :
         binding.playbackCoverPager.apply {
             adapter = coverAdapter
             registerOnPageChangeCallback(OnCoverChangedCallback(queueModel))
+            val recycler = VP_RECYCLER_FIELD.get(this@apply) as RecyclerView
+            recycler.isNestedScrollingEnabled = false
         }
 
         // Set up marquee on song information, alongside click handlers that navigate to each
@@ -307,4 +309,8 @@ class PlaybackPanelFragment :
             }
         }
     }
+    
+    private companion object {
+        val VP_RECYCLER_FIELD: Field by lazyReflectedField(ViewPager2::class, "mRecyclerView")
+    }
 }