Speedup initial android startup on some devices by factor 10 or more

build/android/Makefile

@@ -629,6 +629,7 @@ assets : $(ASSETS_TIMESTAMP)
 	find . -name "timestamp" -exec rm {} \; ;                                  \
 	find . -name "*.blend" -exec rm {} \; ;                                    \
 	ls -R | grep ":$$" | sed -e 's/:$$//' -e 's/\.//' -e 's/^\///' > "index.txt"; \
+	find Minetest >"filelist.txt";                                             \
 	cp ${ROOT}/${ASSETS_TIMESTAMP} ${ROOT}/${ASSETS_TIMESTAMP}.old;            \
 	else                                                                       \
 		echo "nothing to be done for assets";                                  \