Allows selecting up to 5 images using the Pick Visual Media API

**** New Integration: ImagePicker ****
---> Allows selecting up to 5 images using the PickVisualMedia API.
--> Handles camera or video input through the onCameraOrImageOrVideoUriPrepared callback.

---> The ImagePicker constructor accepts a maxItems parameter to limit the number of selectable images.

Note ::: [When launching the activity, the picker uses the minimum of maxItems and PickVisualMediaRequest.maxItems to enforce the selection limit.]