fix: Add build script and fix manifest

- Add build-apk.sh for easy compilation
- Simplify AndroidManifest.xml
- Fix themes.xml to use basic Android themes
- Enable BuildConfig
- Add okhttp-dnsoverhttps dependency

android-sdk/platforms/android-34/data/res/drawable-nodpi/vpn_disconnected.xml

@@ -0,0 +1,24 @@
+<!--
+Copyright (C) 2016 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="48dp"
+        android:height="48dp"
+        android:viewportWidth="48.0"
+        android:viewportHeight="48.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M25.3,20c-1.65,-4.66 -6.08,-8 -11.3,-8 -6.63,0 -12,5.37 -12,12s5.37,12 12,12c5.22,0 9.65,-3.34 11.3,-8H34v8h8v-8h4v-8H25.3zM14,28c-2.21,0 -4,-1.79 -4,-4s1.79,-4 4,-4 4,1.79 4,4 -1.79,4 -4,4z"/>
+</vector>