IVGCVSW-7202 Add Android NDK build targets to build-tool

* Changed build tool scripts to also target Android OS
* Updated Dockerfile to Ubuntu 20.04

Signed-off-by: John Mcloughlin <john.mcloughlin@arm.com>
Change-Id: I6905c205d8870e1628e4885743d9131cb1f11276
diff --git a/build-tool/docker/Dockerfile b/build-tool/docker/Dockerfile
index 2102054..a60a4d5 100644
--- a/build-tool/docker/Dockerfile
+++ b/build-tool/docker/Dockerfile
@@ -1,12 +1,12 @@
 #
-# Copyright © 2022 Arm Ltd and Contributors. All rights reserved.
+# Copyright © 2022-2023 Arm Ltd and Contributors. All rights reserved.
 # SPDX-License-Identifier: MIT
 #
 
 # Default build type is 'production'. Use 'dev' if supplying custom Arm NN / ACL repos from host
 ARG BUILD_TYPE=production
 
-ARG UBUNTU_VERSION=18.04
+ARG UBUNTU_VERSION=20.04
 FROM ubuntu:${UBUNTU_VERSION} AS build-production
 
 ENV DEBIAN_FRONTEND noninteractive