--list-plugins should not start init step

Init step should exit after showing list of avaliable plugins.

Change-Id: I013c24631de2faa9eb14985e9662807e30ca5fb7
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>

gerrit-pgm/src/main/java/com/google/gerrit/pgm/BaseInit.java

@@ -75,7 +75,9 @@ public class BaseInit extends SiteProgram {
   @Override
   public int run() throws Exception {
     final SiteInit init = createSiteInit();
-    beforeInit(init);
+    if (beforeInit(init)) {
+      return 0;
+    }
 
     init.flags.autoStart = getAutoStart() && init.site.isNew;
     init.flags.skipPlugins = skipPlugins();
@@ -108,7 +110,8 @@ public class BaseInit extends SiteProgram {
     return false;
   }
 
-  protected void beforeInit(SiteInit init) throws Exception {
+  protected boolean beforeInit(SiteInit init) throws Exception {
+    return false;
   }
 
   protected void afterInit(SiteRun run) throws Exception {

gerrit-pgm/src/main/java/com/google/gerrit/pgm/Init.java

@@ -76,7 +76,7 @@ public class Init extends BaseInit {
   }
 
   @Override
-  protected void beforeInit(SiteInit init) throws Exception {
+  protected boolean beforeInit(SiteInit init) throws Exception {
     ErrorLogFile.errorOnlyConsole();
 
     if (!skipPlugins) {
@@ -92,8 +92,10 @@ public class Init extends BaseInit {
         } else {
           ui.message("No plugins found.\n");
         }
+        return true;
       }
     }
+    return false;
   }
 
   @Override