Execute a single batch updateconf in CcmBridge

Previously, every configuration option set in a CCM cluster would
get passed as a separate call to "ccm updateconf". After 
scylladb/scylla-ccm#410 was merged, this way stopped working correctly
as it seems like only the first "ccm updateconf" was correctly applied.
Moreover, during the investigation of the issue, it was found that
in case of Scylla, "ccm updateconf client_encryption_options.[OPTION]"
wouldn't get properly filled in (even before scylladb/scylla-ccm#410),
as only a single option from "client_encryption_options.*"
would get persisted.

This change fixes the issue by not issuing separate "ccm updateconf",
but by collecting all configuration options and batching them to
a single "ccm updateconf" call. This follows the implementation in
Java Driver 3.x.

Author: avelanarius

test-infra/src/main/java/com/datastax/oss/driver/api/testinfra/ccm/CcmBridge.java

@@ -302,12 +302,20 @@ public void create() {
           Arrays.stream(nodes).mapToObj(n -> "" + n).collect(Collectors.joining(":")),
           createOptions.stream().collect(Collectors.joining(" ")));
 
+      // Collect all cassandraConfiguration (and others) into a single "ccm updateconf" call.
+      // Works around the behavior introduced in https://github.com/scylladb/scylla-ccm/pull/410
+      StringBuilder updateConfArguments = new StringBuilder();
+
       for (Map.Entry<String, Object> conf : cassandraConfiguration.entrySet()) {
-        execute("updateconf", String.format("%s:%s", conf.getKey(), conf.getValue()));
+        updateConfArguments.append(conf.getKey()).append(':').append(conf.getValue()).append(' ');
       }
       if (getCassandraVersion().compareTo(Version.V2_2_0) >= 0 && !SCYLLA_ENABLEMENT) {
         // @IntegrationTestDisabledScyllaJVMArgs @IntegrationTestDisabledScyllaUDF
-        execute("updateconf", "enable_user_defined_functions:true");
+        updateConfArguments.append("enable_user_defined_functions:true").append(' ');
+      }
+
+      if (updateConfArguments.length() > 0) {
+        execute("updateconf", updateConfArguments.toString());
       }
       if (DSE_ENABLEMENT) {
         for (Map.Entry<String, Object> conf : dseConfiguration.entrySet()) {