update the host files to point to accessible docker container names for backends

added testing for this, including mock backend server.

dockerfiles/services/sslproxy/hosts/abcapi.xai-corp.net.conf

@@ -8,7 +8,7 @@ proxy_cache_path /data/nginx/cache/abcapi levels=1:2 keys_zone=abcapi:10m max_si
 
 server {
     # this is the internal Docker DNS, cache only for 30s
-    resolver 127.0.0.11 valid=30s;
+    resolver 127.0.0.11 valid=5s;
 
     set $backend http://abc-api_nginx;