Generate NetworkStackNext manifest from xml

Instead of a genrule, use an actual manifest merge with a separate
AndroidManifest_Next.xml for NetworkStackNext.

This is necessary as the tooling does not support injecting the train
version number to a genrule, it needs an actual manifest file.

Bug: 148907674
Test: m NetworkStackNext, diff aapt dump xmltree from parent build
Change-Id: I84d97e9108616cac1bd737dc0e4f250cc96a73da
diff --git a/AndroidManifest_Next.xml b/AndroidManifest_Next.xml
new file mode 100644
index 0000000..02fcb64
--- /dev/null
+++ b/AndroidManifest_Next.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+ * Copyright (C) 2020 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.networkstack"
+          android:sharedUserId="android.uid.networkstack"
+          android:versionCode="300000000"
+          android:versionName="R-next">
+</manifest>