Use correct slot id for client certs in network config.

- Now all client cert related Shill properties are set through client_cert_util.*
- Slot id is obtained from the slot in which the private key is stored
- All client cert pattern resolution now happens in ClientCertResolver

BUG=358366

Review URL: https://codereview.chromium.org/421113002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@286583 0039d316-1c4b-4281-b951-d872f2087c98
17 files changed