Update android texture loader store

Author: frenzibyte

osu.Framework.Android/Graphics/Textures/AndroidTextureLoaderStore.cs

@@ -17,7 +17,7 @@ public AndroidTextureLoaderStore(IResourceStore<byte[]> store)
         {
         }
 
-        protected override Image<TPixel> ImageFromStream<TPixel>(Stream stream)
+        protected override PremultipliedImage ImageFromStream(Stream stream)
         {
             using (var bitmap = BitmapFactory.DecodeStream(stream))
             {
@@ -34,7 +34,7 @@ protected override Image<TPixel> ImageFromStream<TPixel>(Stream stream)
                 }
 
                 bitmap.Recycle();
-                return Image.LoadPixelData<TPixel>(result, bitmap.Width, bitmap.Height);
+                return PremultipliedImage.FromStraight(Image.LoadPixelData<Rgba32>(result, bitmap.Width, bitmap.Height));
             }
         }
     }