upgrades udacity's android sources to use the gradle-3.0 plugin of Android Studio 3 -- https://github.com/gshadows/scripts/blob/master/convert-udacity-gradle.sh is more elaborate, this also fixes T10.x

fix_udacity_android.sh

#! /bin/sh
### upgrades udacity's android sources to use the gradle-3.0 plugin of Android Studio 3.
### run this script from the directory you want to upgrade to 
for i in $(git ls-files '*build.gradle'); do
    grep 'vectorDrawables' $i && echo "$(/bin/pwd)/$i already upgraded? contains vectorDrawables" && exit 1
    sed -i'.bak' -e "s/classpath 'com.android.tools.build:gradle:2.2.3'/classpath 'com.android.tools.build:gradle:3.0.0'/g" $i;
    sed -i'.bak' "s/buildToolsVersion ['\"]25.0.2['\"]/buildToolsVersion '26.0.2'/g" $i;
    sed -i'.bak' -e "s/defaultConfig {/defaultConfig{\n        vectorDrawables.useSupportLibrary = true/g" $i;
    sed -i'.bak' -e "s/^dependencies {/dependencies {\n    compile 'com.android.support:appcompat-v7:26.1.0'/g" $i;
done

for i in $(git ls-files '*gradle-wrapper.properties'); do
    sed -i'.bak' -e "s/gradle-3.3-all.zip/gradle-4.1-all.zip/g" $i;
done