3.8.3 Release

Misc Fixes 🐛 & Improvements 🔨

• Fixes ConcurrentModificationException errors, regression bug in 3.8.0 Issue #465
• Refactored internal SharedPreferences writes for improved performance. PR #479
• Updated to gms dependency range to include 12.+
  • If you get the duplicate com.google.android.gms.license build error add OneSignal-Gradle-Plugin to your project.
• Fixes logoutEmail error when using emailAuthHash
• Fixes race condition subscription issue when promptLocation is called after init Issue #477
• Unity - Fixed missing OneSignalUnityProxy class when using Proguard
  • Issue OneSignal/OneSignal-Unity-SDK#86