[CrOS Network] Fix broken connections to EAP-TLS Wi-Fi networks.

When configuring networks, the networking UI compiles a dictionary of
properties describing the new network to configure. In this particular
case, the "clientCertPkcs11Id" field of the dictionary was misspelled
using capital letters: "clientCertPKCS11Id".

This CL corrects the spelling and fixes this connection flow.

Bug: 1019936
Change-Id: I421c340a36c3a8b9404b07e76aa86f6cffae9829
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1915279
Auto-Submit: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715160}

ui/webui/resources/cr_components/chromeos/network/network_config.js

@@ -1479,7 +1479,7 @@ Polymer({
 
     const pkcs11Id = this.getUserCertPkcs11Id_();
     eap.clientCertType = pkcs11Id ? 'PKCS11Id' : 'None';
-    eap.clientCertPKCS11Id = pkcs11Id || '';
+    eap.clientCertPkcs11Id = pkcs11Id || '';
   },
 
   /**