[Clank CBCM] Better chrome://management dynamic padding

The chrome://management page padding is dynamic depending on the device. This CL sets the correct padding by defining two XML @dimen sizes instead of programmatically changing the size.

Bug: 1290667
Change-Id: If57db834efabe5721dc3287abd5a0c0ccf57c384
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3422107
Commit-Queue: Og Astorga <ogastorga@chromium.org>
Auto-Submit: Og Astorga <ogastorga@chromium.org>
Reviewed-by: Sky Malice <skym@chromium.org>
Commit-Queue: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/main@{#964357}