Install latest Android sdk and ndk.
It also runs update for SDK API level 18, latest SDK- and platform-
tools and build-tools version 23.0.3.
Build-tools version 23.0.3 is the latest usable version
for Red Hat 6. Newer version of build-tools, version 24.x.x,
requires GLIBC_2.14, which is not available in Red Hat 6.
Change-Id: Iddc353674a65e0af7a9036d9296b9c2933fa114f
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
