Swapped the onboarding activity for a simple dialog

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

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?><!--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  Look4Sat. Amateur radio satellite tracker and pass predictor.
+  Copyright (C) 2019, 2020 Arty Bishop (bishop.arty@gmail.com)
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along
+  with this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-->
+
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <stroke
+        android:width="0dp"
+        android:color="@color/greySurface" />
+    <solid android:color="@color/greySurface" />
+    <corners android:radius="8dp" />
+</shape>