MLProgress: lower delay to show progressBar

This is linked to commit 89b91b2a in which the delay between updated from the MediaParsingService was removed. This means that the occasional null update sent by the medialibrary when changing task will cancel the task to show the progress bar before it's 1000L delay is done. On low end devices this delay isn't a problem, but on faster devices the delay of 1000L causes the progressBar to be canceled before even being shown.

Draft because I wan't to test this on more devices to be sure it doesn't create other issues