These previews will be only available for images cached in the cache used by Picasso.
The Bitmap of the content is compressed in JPEG 90 and saved inside the application cache folder under the name android_share_sheet_image_preview.jpg.
The current image will be, of course, always overwritten by the next one and cleared when the application cache is cleared.
Fix the error due to the rebase on the dev branch of this branch
Add a shareText method in the ShareUtils class which has 3 parameters and calls
the original shareText method with an empty string for the
imagePreviewUrl param.
Rename URLHandler and KoreUtil classes to InternalUrlsHandler and KoreUtils.
Move InternalUrlsHandler, KoreUtils, TextLinkfier, ShareUtils classes to external_communication subpackage.
Remove unused param showPreviewText in shareText method of ShareUtils class.
Add initial work to be able to display an image preview of the content shared (not for downloads).
Use a better regular expression to parse timestamps in plain text descriptions.
