android: use vector drawables for icon, shrink to fit square keylines

Fixes tailscale/tailscale#485

Signed-off-by: Elias Naur <mail@eliasnaur.com>

android/src/main/res/drawable/ic_launcher_foreground.xml

@@ -0,0 +1,36 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="100"
+    android:viewportHeight="100">
+  <group android:translateX="20"
+      android:translateY="20">
+    <path
+        android:pathData="M15,30.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#FFFDFA"/>
+    <path
+        android:pathData="M30,30.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#FFFDFA"/>
+    <path
+        android:pathData="M15,45.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#54514D"/>
+    <path
+        android:pathData="M45,45.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#54514D"/>
+    <path
+        android:pathData="M30,45.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#FFFDFA"/>
+    <path
+        android:pathData="M45,30.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#FFFDFA"/>
+    <path
+        android:pathData="M15,15.0002m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#54514D"/>
+    <path
+        android:pathData="M30,14.9999m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#54514D"/>
+    <path
+        android:pathData="M45,14.9999m-5,0a5,5 0,1 1,10 0a5,5 0,1 1,-10 0"
+        android:fillColor="#54514D"/>
+  </group>
+</vector>

android/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
     <background android:drawable="@color/ic_launcher_background"/>
-    <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+    <foreground android:drawable="@drawable/ic_launcher_foreground"/>
 </adaptive-icon>

android/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
     <background android:drawable="@color/ic_launcher_background"/>
-    <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+    <foreground android:drawable="@drawable/ic_launcher_foreground"/>
 </adaptive-icon>