Disable wallet in countries where it's not supported, take 2.

Only disable it if there's no indication the user might be interested in US addresses. App locale is not taken into account because many international users set theirs to en-US.

BUG=323641

Review URL: https://codereview.chromium.org/106033007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243735 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243735