Migrate buttons to gm3 material style

Change button perceived height from 36dp to 40dp by updating
button_bg_vertical_inset from 6dp to 4dp;
Make button fully rounded by updating button_compat_corner_radius
from 4dp to 500dp;
Update the button baseline color for light & dark themes
and normal & disabled states.
This change updates modern_blue_600, which will affect other
surfaces a well.

Bug: 1217139
Change-Id: Id489a4a0bc952d13b58f28e9808e52f03eea7209
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2961185
Commit-Queue: Shu Yang <shuyng@google.com>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Sinan Sahin <sinansahin@google.com>
Reviewed-by: Sky Malice <skym@chromium.org>
Reviewed-by: Lijin Shen <lazzzis@google.com>
Cr-Commit-Position: refs/heads/master@{#893237}