Fix React Native 0.79 Kotlin compilation errors

- Fix currentActivity reference in CameraViewModule
- Convert Map to MutableMap in CameraViewManager for RN 0.79 compatibility

package/android/src/main/java/com/mrousavy/camera/CameraViewManager.kt

@@ -32,7 +32,7 @@ class CameraViewManager : ViewGroupManager<CameraView>() {
       .put("cameraError", MapBuilder.of("registrationName", "onError"))
       .put("cameraCodeScanned", MapBuilder.of("registrationName", "onCodeScanned"))
       .put("onVideoChunkReady", MapBuilder.of("registrationName", "onVideoChunkReady"))
-      .build()
+      .build()?.toMutableMap()
 
   override fun getName(): String = TAG