Replace hardcoded plugin name with @PluginName

Change-Id: I2c4a1852c01ad640a31c8850320e66f0bef2445d

src/main/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSession.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSession.java b/src/main/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSession.java
index 475ff41..2acec1c 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSession.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/websession/flatfile/FlatFileWebSession.java
@@ -14,6 +14,7 @@
 
 package com.googlesource.gerrit.plugins.websession.flatfile;
 
+import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.annotations.RootRelative;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.httpd.CacheBasedWebSession;
@@ -51,8 +52,9 @@
     @Provides
     @Singleton
     @WebSessionDir
-    File getWebSessionDir(SitePaths site, PluginConfigFactory cfg) {
-      return new File(cfg.getFromGerritConfig("websession-flatfile").getString(
+    File getWebSessionDir(SitePaths site, PluginConfigFactory cfg,
+        @PluginName String pluginName) {
+      return new File(cfg.getFromGerritConfig(pluginName).getString(
           "directory", site.site_path + "/websessions"));
     }
   }

src/main/resources/Documentation/config.md

diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 8bc207c..09a49d5 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -8,7 +8,7 @@
 main Gerrit config file: $site_dir/etc/gerrit.config.  This
 location defaults to $site_dir/websessions.
 
-  [plugin "websession-flatfile"]
+  [plugin "@PLUGIN@"]
     directory = <disk_cache_directory>
   # NOTE: <disk_cache_directory> can be any location on the
   # shared filesystem that can be accessed by all servers,