Fix build android build

[shtreb]

Description

Change variable type from Array to Array? and handling signature variable after init

Type of Change

• [ ] ✨ New feature (non-breaking change which adds functionality)
• [X] 🛠️ Bug fix (non-breaking change which fixes an issue)
• [ ] ❌ Breaking change (fix or feature that would cause existing functionality to change)
• [ ] 🧹 Code refactor
• [ ] ✅ Build configuration change
• [ ] 📝 Documentation
• [ ] 🗑️ Chore