apmanager: add init script

Add init script to start apmanager daemon during system startup.

BUG=chromium:442188
TEST=emerge-$BOARD apmanager and manually verify apmanager daemon is
     running after system is restarted.
CQ-DEPEND=CL:235643

Change-Id: Ic6bb018fc41031701cb5f360e2c1c9e37ffe360e
Reviewed-on: https://chromium-review.googlesource.com/235644
Reviewed-by: Peter Qiu <zqiu@chromium.org>
Tested-by: Peter Qiu <zqiu@chromium.org>
Commit-Queue: Peter Qiu <zqiu@chromium.org>
diff --git a/init/apmanager.conf b/init/apmanager.conf
new file mode 100644
index 0000000..06dd54f
--- /dev/null
+++ b/init/apmanager.conf
@@ -0,0 +1,13 @@
+# Copyright 2014 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+description   "Run the access point manager daemon"
+author        "chromium-os-dev@chromium.org"
+
+start on starting system-services
+stop on stopping system-services
+
+env APMANAGER_LOG_LEVEL=0
+
+exec /usr/bin/apmanager --v="${APMANAGER_LOG_LEVEL}"