Make the policy fetch for first time login blocking

The CL makes policy fetching for first time login blocking for all users, except the ones that are known to be non-enterprise users.

BUG=334584

Review URL: https://codereview.chromium.org/330843002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282925 0039d316-1c4b-4281-b951-d872f2087c98
    UserCloudPolicyManagerFactoryChromeOS::GetInstance() {
  return Singleton<UserCloudPolicyManagerFactoryChromeOS>::get();
}

    UserCloudPolicyManagerFactoryChromeOS::GetInstance() {
  return Singleton<UserCloudPolicyManagerFactoryChromeOS>::get();
}
