Run compsvc on CompOS boot

Bug: 186126809
Test: 1. follow microdroid/README.md except payload.img:
        $ adb shell 'cd /data/local/tmp/microdroid;    \
           /apex/com.android.virt/bin/mk_payload       \
           /apex/com.android.compos/etc/payload_config.json \
           payload.img'
	$ adb shell 'chmod go+r /data/local/tmp/microdroid/payload*'
      2. adb shell /apex/com.android.virt/bin/vm run \
           /data/local/tmp/microdroid/microdroid.json

Change-Id: I03cc937c0f82cbcc4fd1064ce2135619f22b4170
diff --git a/compos/apk/AndroidManifest.xml b/compos/apk/AndroidManifest.xml
new file mode 100644
index 0000000..1e9352b
--- /dev/null
+++ b/compos/apk/AndroidManifest.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2021 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.
+-->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+      package="com.android.compos.payload">
+    <application android:label="CompOS" />
+</manifest>