Enlist the newly core plugin-manager plugin itself

Change-Id: Ic5f0dac5c106ec7ff7ac4480e0b818ff2f1cf8db

src/main/java/com/googlesource/gerrit/plugins/manager/repository/CorePluginsDescriptions.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/manager/repository/CorePluginsDescriptions.java b/src/main/java/com/googlesource/gerrit/plugins/manager/repository/CorePluginsDescriptions.java
index 1591316..efb0e10 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/manager/repository/CorePluginsDescriptions.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/manager/repository/CorePluginsDescriptions.java
@@ -34,6 +34,8 @@
     pluginsDescriptions.put("download-commands", "Adds the standard download schemes and commands");
     pluginsDescriptions.put("gitiles", "Plugin running Gitiles alongside a Gerrit server");
     pluginsDescriptions.put("hooks", "Old-style fork+exec hooks");
+    pluginsDescriptions.put(
+        "plugin-manager", "Adds support for discovering and installing other plugins");
     pluginsDescriptions.put("replication", "Copies to other servers using the Git protocol");
     pluginsDescriptions.put(
         "reviewnotes", "Annotates merged commits using notes on refs/notes/review");