Prevent BottomSheet tap leaking to nav panels.

With the BottomSheet open, while trying to tap one of the
controls (esp. add to playlist and favorite buttons) it is easy to
miss the touch point and tap directly on the BottomSheet.

This tap bleeds through to whatever fragment is currently displayed in
the navigation area (Artist, Album, Playlists, etc.).  That tap
changes the view in the navigation panel.  For example, if the Artist
fragment it current, it will open a list of the artists albums.

That change may be surprising when the BottomSheet is toggled closed.
So, ignore BottomSheet taps outside the active controls.

app/src/main/java/audio/funkwhale/ffa/views/NowPlayingBottomSheet.kt

@@ -3,6 +3,7 @@ package audio.funkwhale.ffa.views
 import android.content.Context
 import android.util.AttributeSet
 import android.util.TypedValue
+import android.view.MotionEvent
 import android.view.View
 import android.view.ViewGroup
 import android.widget.FrameLayout
@@ -52,6 +53,8 @@ class NowPlayingBottomSheet @JvmOverloads constructor(
     } ?: hide()
   }
 
+  override fun onTouchEvent(event: MotionEvent): Boolean = true
+
   fun addBottomSheetCallback(callback: BottomSheetCallback) {
     behavior.addBottomSheetCallback(callback)
   }