Include licensed field in PluginInfo xcontent and toString (#65830)

When #65409 was merged, it didn't include the new PluginInfo field licensed in the
toString() or toXContent() outputs. This PR adds them and updates the tests accordingly.

Author: pugnascotia

distribution/tools/plugin-cli/src/test/java/org/elasticsearch/plugins/ListPluginsCommandTests.java

@@ -154,6 +154,7 @@ public void testPluginWithVerbose() throws Exception {
                 "Elasticsearch Version: " + Version.CURRENT.toString(),
                 "Java Version: 1.8",
                 "Native Controller: false",
+                "Licensed: false",
                 "Type: isolated",
                 "Extended Plugins: []",
                 " * Classname: org.fake"
@@ -177,6 +178,7 @@ public void testPluginWithNativeController() throws Exception {
                 "Elasticsearch Version: " + Version.CURRENT.toString(),
                 "Java Version: 1.8",
                 "Native Controller: true",
+                "Licensed: false",
                 "Type: isolated",
                 "Extended Plugins: []",
                 " * Classname: org.fake"
@@ -201,6 +203,7 @@ public void testPluginWithVerboseMultiplePlugins() throws Exception {
                 "Elasticsearch Version: " + Version.CURRENT.toString(),
                 "Java Version: 1.8",
                 "Native Controller: false",
+                "Licensed: false",
                 "Type: isolated",
                 "Extended Plugins: []",
                 " * Classname: org.fake",
@@ -212,6 +215,7 @@ public void testPluginWithVerboseMultiplePlugins() throws Exception {
                 "Elasticsearch Version: " + Version.CURRENT.toString(),
                 "Java Version: 1.8",
                 "Native Controller: false",
+                "Licensed: false",
                 "Type: isolated",
                 "Extended Plugins: []",
                 " * Classname: org.fake2"

server/src/main/java/org/elasticsearch/plugins/PluginInfo.java

@@ -393,9 +393,7 @@ public String getJavaOpts() {
     }
 
     /**
-     * Whether a license must be accepted before this plugin can be installed.
-     *
-     * @return {@code true} if a license must be accepted.
+     * Whether this plugin is subject to the Elastic License.
      */
     public boolean isLicensed() {
         return isLicensed;
@@ -413,6 +411,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field("classname", classname);
             builder.field("extended_plugins", extendedPlugins);
             builder.field("has_native_controller", hasNativeController);
+            builder.field("licensed", isLicensed);
             builder.field("type", type);
             if (type == PluginType.BOOTSTRAP) {
                 builder.field("java_opts", javaOpts);
@@ -456,6 +455,7 @@ public String toString(String prefix) {
             .append(prefix).append("Elasticsearch Version: ").append(elasticsearchVersion).append("\n")
             .append(prefix).append("Java Version: ").append(javaVersion).append("\n")
             .append(prefix).append("Native Controller: ").append(hasNativeController).append("\n")
+            .append(prefix).append("Licensed: ").append(isLicensed).append("\n")
             .append(prefix).append("Type: ").append(type).append("\n");
 
         if (type == PluginType.BOOTSTRAP) {

x-pack/plugin/monitoring/src/test/java/org/elasticsearch/xpack/monitoring/collector/cluster/ClusterStatsMonitoringDocTests.java

@@ -541,6 +541,7 @@ public void testToXContent() throws IOException {
                           + "\"classname\":\"_plugin_class\","
                           + "\"extended_plugins\":[],"
                           + "\"has_native_controller\":false,"
+                          + "\"licensed\":false,"
                           + "\"type\":\"isolated\""
                         + "}"
                       + "],"