Give up on using vector drawables for launch icons

Instead use svg files in art/ and a script to build the png files.

art/generate-pngs.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+for DENSITY in mdpi hdpi xhdpi xxhdpi xxxhdpi; do
+	case $DENSITY in
+		mdpi) SIZE=48;;
+		hdpi) SIZE=72;;
+		xhdpi) SIZE=96;;
+		xxhdpi) SIZE=144;;
+		xxxhdpi) SIZE=192;;
+	esac
+
+	FOLDER=../app/src/main/res/mipmap-$DENSITY
+	mkdir -p $FOLDER
+
+	for FILE in ic_launcher ic_launcher_round; do
+		PNG=$FOLDER/$FILE.png
+		rsvg-convert -w $SIZE -h $SIZE $FILE.svg > $PNG
+		zopflipng -y $PNG $PNG
+	done
+done