i found that's possible to crop rectangles using the built-in Android cropping handler.(com.android.camera.action.CROP). To crop rectangles you need to remove the following parameters of the example that i passed before:
intent.putExtra("outputX", 200); //Set this to define the max size of the output bitmap
intent.putExtra("outputY", 200); //Set this to define the max size of the output bitmap
intent.putExtra("aspectX", 1); //Set this to define the X aspect ratio of the shape
intent.putExtra("aspectY", 1); //Set this to define the Y aspect ratio of the shape
Setting the aspectX and aspectY will force the android to move both sides of the shape when you move one of them. Comment those lines and you'll be free to move the shape.