Update to latest build tools version

I tried out your image, unfortunately my build failed because I am using build tools 24.0.3.
So I decided to make a pull request and wait :)

Dockerfile

@@ -9,7 +9,7 @@ FROM ubuntu:16.04
 MAINTAINER Jan Grewe <jan@faked.org>
 
 ENV VERSION_SDK_TOOLS "25.2.2"
-ENV VERSION_BUILD_TOOLS "24.0.2"
+ENV VERSION_BUILD_TOOLS "24.0.3"
 ENV VERSION_TARGET_SDK "24"
 
 ENV SDK_PACKAGES "build-tools-${VERSION_BUILD_TOOLS},android-${VERSION_TARGET_SDK},addon-google_apis-google-${VERSION_TARGET_SDK},platform-tools,extra-android-m2repository,extra-android-support,extra-google-google_play_services,extra-google-m2repository"