Replace app icon with walkie-talkie (icons8 style)

- Adaptive icon foreground is now the purple walkie-talkie PNG on the
  dark background, replaces the white mic vector
- Notification small icon now uses the walkie silhouette

app/src/main/java/ru/ua1zbe/svxremote/SvxService.kt

@@ -67,7 +67,7 @@ class SvxService : Service(), ReflectorClient.Callbacks {
         val n = Notification.Builder(this, "svx")
             .setContentTitle("SVXRemote")
             .setContentText(text)
-            .setSmallIcon(android.R.drawable.ic_menu_call)
+            .setSmallIcon(R.drawable.ic_launcher_fg)
             .setOngoing(true)
             .setContentIntent(contentIntent)
             .build()

app/src/main/res/drawable/ic_launcher_fg.xml

@@ -1,16 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="108dp"
-    android:height="108dp"
-    android:viewportWidth="108"
-    android:viewportHeight="108">
-    <group
-        android:translateX="30"
-        android:translateY="30"
-        android:scaleX="1.5"
-        android:scaleY="1.5">
-        <path
-            android:fillColor="#FFFFFF"
-            android:pathData="M12,14c1.66,0 2.99,-1.34 2.99,-3L15,5c0,-1.66 -1.34,-3 -3,-3S9,3.34 9,5v6c0,1.66 1.34,3 3,3zM17.3,11c0,3 -2.54,5.1 -5.3,5.1S6.7,14 6.7,11L5,11c0,3.41 2.72,6.23 6,6.72L11,21h2v-3.28c3.28,-0.48 6,-3.3 6,-6.72h-1.7z" />
-    </group>
-</vector>