Add 'blank_screen' util.

This can be transitioned to by init to shutdown the
screen thereby preventing init from either depending
on binder or accessing halified sysnodes directly.

Bug: 70846424
Test: manual + init use
Change-Id: I86893ee5d7118547cd073297c0626e474f366b82
diff --git a/light/utils/Android.bp b/light/utils/Android.bp
new file mode 100644
index 0000000..ebcbfa2
--- /dev/null
+++ b/light/utils/Android.bp
@@ -0,0 +1,30 @@
+//
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Turns off the screen.
+// Canonical usage is for init (which can't talk to hals directly).
+cc_binary {
+    name: "blank_screen",
+    init_rc: ["blank_screen.rc"],
+    srcs: ["main.cpp"],
+    shared_libs: [
+        "android.hardware.light@2.0",
+        "libbase",
+        "libhidlbase",
+        "libhidltransport",
+        "libutils",
+    ],
+}