Expose supported UIs in GetServerInfo

Requires moving GerritInfo into gerrit-server.

Change-Id: I447c29c553e693c4aa02665610101588bdde38c6

Documentation/rest-api-config.txt

diff --git a/Documentation/rest-api-config.txt b/Documentation/rest-api-config.txt
index 454a30d..de21034 100644
--- a/Documentation/rest-api-config.txt
+++ b/Documentation/rest-api-config.txt
@@ -123,7 +123,10 @@
     "gerrit": {
       "all_projects": "All-Projects",
       "all_users": "All-Users"
-      "doc_search": true
+      "doc_search": true,
+      "web_uis": [
+        "gwt"
+      ]
     },
     "sshd": {},
     "suggest": {
@@ -1469,6 +1472,9 @@
 |`report_bug_text`   |optional, not set if default|
 link:config-gerrit.html#gerrit.reportBugText[Display text for report
 bugs link].
+|`web_uis`           ||
+List of web UIs supported by the HTTP server. Possible values are `GWT`
+and `POLYGERRIT`.
 |=================================
 
 [[hit-ration-info]]