[DefaultOffline]: Increase weight of offline icon.

The SVG from the icon library was downloaded from the
500 weight set, but should have been from the 600 weight
set.

Bug: 1441059
Change-Id: I5b55553c7d204e64793af4fe0d3b714498192175
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4521031


Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Auto-Submit: Finnur Thorarinsson <finnur@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1148006}