SOC-3514 [Activity Composer] i18n of Attach button when sharing a link

Fix description:
* Use the resource key for Attach button
* Remove two redundant variables
SOC-3473 : file activity  look bad when resize window
SOC-3249 | [Profile] Feedback about Edit Experience.
SOC-3449 | Wrong last updated time in Rest response for user activity stream
Merge commit '33f1c1bb6c68adf00e5b1f01ce955cf6644b11cf' into HEAD