Add basic init classes of gerrit-pgm again to plugin api

Since the tentative switch to Buck, plugins could no longer hook into
gerrit's init procedure, as the plugin api no longer exposed the
required classes. We re-add the required classes to make hooks-its
compile against the plugin api.

Change-Id: I0da8089c718f4a3c246ccc34cc45ae2f6b7d1aab

BUCK

@@ -48,6 +48,7 @@ genrule(
 
 PLUGIN_API = [
   '//gerrit-server:server',
+  '//gerrit-pgm:init-api',
   '//gerrit-sshd:sshd',
   '//gerrit-httpd:httpd',
 ]

gerrit-pgm/BUCK

@@ -1,8 +1,38 @@
+INIT_SRCS = ['src/main/java/com/google/gerrit/pgm/' + n for n in [
+  'init/InitFlags.java',
+  'init/InitStep.java',
+  'init/InitStep.java',
+  'init/InstallPlugins.java',
+  'init/Section.java',
+  'util/ConsoleUI.java',
+  'util/Die.java',
+]]
+
+java_library(
+  name = 'init-api',
+  srcs = INIT_SRCS,
+  deps = [
+    '//gerrit-server:server',
+    '//lib:jsr305',
+    '//lib/guice:guice',
+    '//lib/guice:guice-assistedinject',
+    '//lib/jgit:jgit',
+  ],
+  visibility = ['PUBLIC'],
+)
+
+java_sources(
+  name = 'init-api-src',
+  srcs = INIT_SRCS,
+  visibility = ['PUBLIC'],
+)
+
 java_library2(
   name = 'pgm',
-  srcs = glob(['src/main/java/**/*.java']),
+  srcs = glob(['src/main/java/**/*.java'], excludes = INIT_SRCS),
   resources = glob(['src/main/resources/**/*']),
   deps = [
+    ':init-api',
     '//gerrit-cache-h2:cache-h2',
     '//gerrit-common:server',
     '//gerrit-extension-api:api',