refactor: avoid tight coupling by using dependency injection

[alexgerardojacinto]

Problem

• Cyclic dependency between CameraPlugin and flow classes (IonCameraFlow and LegacyCameraFlow)
• Flows were receiving CameraPlugin instance via constructor and calling back to plugin methods
• This created tight coupling: CameraPlugin → Flows → CameraPlugin
• Made testing difficult and violated dependency inversion principle

Solution: Constructor Dependency Injection

1. Created PermissionHelper class

• Encapsulates permission-related operations without holding plugin reference
• Uses lambda/function references instead of plugin instance
• Accepts 4 function parameters: isPermissionDeclared, getPermissionState, requestPermissionForAlias, requestPermissionForAliases
• Completely eliminates type dependency on CameraPlugin

2. Refactored IonCameraFlow (Kotlin)

• Changed constructor to accept explicit dependencies: Context, Activity, Bridge, appId, PermissionHelper
• Replaced all plugin.* references with injected dependencies
• No longer holds reference to CameraPlugin

3. Refactored LegacyCameraFlow (Java)

• Changed constructor to accept explicit dependencies: Context, AppCompatActivity, Bridge, appId, PermissionHelper, ActivityStarter
• Created ActivityStarter functional interface for activity result launching (avoids naming conflict with AndroidX's ActivityResultLauncher)
• Replaced all plugin.* references with injected dependencies
• No longer holds reference to CameraPlugin

4. Updated CameraPlugin

• Modified load() method to instantiate flows with explicit dependencies
• Creates PermissionHelper with lambda function references
• Passes concrete dependencies (context, activity, bridge, appId) to flow constructors
• Removed unnecessary wrapper methods (requestLegacyPermissionForAlias, requestLegacyPermissionForAliases)

Benefits

• ✅ Eliminates cyclic dependency - flows only depend on interfaces/primitives, not plugin
• ✅ Improves testability - flows can be unit tested with mock dependencies
• ✅ Better separation of concerns - explicit, clear dependencies via constructor
• ✅ Follows SOLID principles - dependency inversion, interface segregation
• ✅ No behavioral changes - purely structural refactoring, maintains backward compatibility

Files Changed

• New: PermissionHelper.kt - Permission operations wrapper
• Modified: IonCameraFlow.kt - Constructor injection refactor
• Modified: LegacyCameraFlow.java - Constructor injection refactor, added ActivityStarter interface
• Modified: CameraPlugin.kt - Updated flow instantiation with dependencies