policy: Update managed setting icons.

Screenshots available on the bug.

BUG=276956

Review URL: https://codereview.chromium.org/26847002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236218 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236218