4256 [camera] Expand CameraImage DTO with properties for lens aperture, exposure time and ISO.  (cla: yes, waiting for tree to go green, p: camera, platform-ios, platform-android)

4258 [camera] Add Android & iOS implementations for pausing the camera preview  (cla: yes, waiting for tree to go green, p: camera, platform-ios, platform-android)

4259 [camera_web] Add onCameraClosing implementation (cla: yes, waiting for tree to go green, p: camera, platform-web)

4265 [camera] Replace device info with new device_info_plus (cla: yes, waiting for tree to go green, p: camera)

4272 [camera] Fix a disposed camera controller throwing an exception when being replaced in the preview widget. (cla: yes, waiting for tree to go green, p: camera)