Unnecessary Transitions when adding Media from Post or Page through "Add Media" button

[mikeyarce]

When adding Media through the Post or Page "Add Media" button, the media element has a transition that makes them slide in from the right. Here's an example screencast of the issue:

The Media is pulling in this line of code:

.attachments-browser .attachments, .attachments-browser .uploader-inline {
   transition: all 1s ease-in-out 0s; 
}

Which is used for the "Add New" button on the Media page, to make the "Drop files anywhere to upload" transition down from the top.

I'm attaching a patch that just adds more specificity to the CSS so that the transition is only present on those elements on that page instead of on the "Add Media" modal on other pages. Not 100% I used the right top level class for the page, but in my test this seems to work.

[mikeyarce]

Add specificity to transition for "Add New" on Media page

[helen]

ocean90 noticed something along these lines earlier as well. I think some stuff is colliding between the library grid and the media modal, and possibly also with the JS that resizes the images.

That transition also needs to be way faster, like .25s maybe.

[ericlewis]

Related: #28851

[ocean90]

In 29131:

Media Grid: Remove CSS transition from inline uploader.

props ericlewis.
fixes #28840.
see #28851.