* fix(mobile): keep header image when starting selection
* fix(mobile): fade out header actions during selection
Hide the back button and person options menu with the same fade as the
timeline app bar, and block taps on the person name and birthday while
assets are selected.
---------
Co-authored-by: Santo Shakil <santoshakil@users.noreply.github.com>
(cherry picked from commit 745bdd2edf72ce0f75e748e2d68c37b6ea196cc5)
