Media Library can delete user customizations to the media view and therefore should modify the media view more intelligently

Problem/Motivation

From #2962110-119: Add the Media Library module to Drupal core:

[media_library.install is] assuming the original media library view was never customized, but that's not safe. I moved the view to another location, installed media_libray, uninstalled it, and my customization was reverted. We should probably add some checks to verify that the path and menu settings are the default ones before altering them.

Proposed resolution

We should probably add a couple of checks to Media Library's install and/or uninstall routines to confirm that we are not blowing away legitimate customizations users may have made.

Remaining tasks

Fix the problem with a patch, and test the fix with automated tests. Then commit the thing.

User interface changes

None.

API changes

None.

Data model changes

None.