Changed:
- Preload native overlay when init ad client
- Make abstract for class ButtonCustom (don't allow ButtonCustom to be attached to hierarchy)
- Fix LevelEditor (method ClearPreview)
- Update register package:
- Firebase 12.5.0
- Google play game services 2.0.0
- Apple signin 1.4.4
- Ironsource sdk 8.5.1
- UIEffect 5.1.0
- UIParticle 4.10.6
Full Changelog: 3.2.5...3.2.6