I downloaded collection of icons from Android Developers center Each icon in this collection is ordered in forlders according to its resolution: drawable-hdpi, drawable-mdpi
If for some reason you don't want to use the plugin, then here's the script you can use to copy the resources to your android studio project:
echo "..:: Copying resources ::.."
echo "Enter folder:"
read srcFolder
echo "Enter filename with extension:"
read srcFile
cp /Users/YOUR_USER/Downloads/material-design-icons-master/"$srcFolder"/drawable-xxxhdpi/"$srcFile" /Users/YOUR_USER/AndroidStudioProjects/YOUR_PROJECT/app/src/main/res/drawable-xxxhdpi/"$srcFile"/
echo "xxxhdpi copied"
cp /Users/YOUR_USER/Downloads/material-design-icons-master/"$srcFolder"/drawable-xxhdpi/"$srcFile" /Users/YOUR_USER/AndroidStudioProjects/YOUR_PROJECT/app/src/main/res/drawable-xxhdpi/"$srcFile"/
echo "xxhdpi copied"
cp /Users/YOUR_USER/Downloads/material-design-icons-master/"$srcFolder"/drawable-xhdpi/"$srcFile" /Users/YOUR_USER/AndroidStudioProjects/YOUR_PROJECT/app/src/main/res/drawable-xhdpi/"$srcFile"/
echo "xhdpi copied"
cp /Users/YOUR_USER/Downloads/material-design-icons-master/"$srcFolder"/drawable-hdpi/"$srcFile" /Users/YOUR_USER/AndroidStudioProjects/YOUR_PROJECT/app/src/main/res/drawable-hdpi/"$srcFile"/
echo "hdpi copied"
cp /Users/YOUR_USER/Downloads/material-design-icons-master/"$srcFolder"/drawable-mdpi/"$srcFile" /Users/YOUR_USER/AndroidStudioProjects/YOUR_PROJECT/app/src/main/res/drawable-mdpi/"$srcFile"/
echo "mdpi copied"