Improve NanoDroid-Font restoration upon update

CommonInstaller

@@ -230,14 +230,14 @@ detect_mode () {
 	ui_print "${MODE_TEXT}"
 	ui_print " "
 
-	# backup fonts
-	if [[ "$(file ${MODPATH}/system/fonts/Roboto-Regular.ttf)" = *symbolic* ]]; then
-		ui_print " << Backup custom font"
-		CUSTOM_FONT="$(basename $(ls -l ${MODPATH}/system/fonts/Roboto-Regular.ttf | awk -F '->' '{print $2}') .ttf)"
+	[ "${MODE}" = "MAGISK" ] && magisk_install_setup
+
+	if test -h ${MODPATH}/system/fonts/Roboto-Regular.ttf; then
+		CUSTOM_FONT="$(basename $(readlink ${MODPATH}/system/fonts/Roboto-Regular.ttf) .ttf)"
+		ui_print " << Detected NanoDroid-Font (${CUSTOM_FONT})"
 	fi
 
 	if [ "${MODE}" = "MAGISK" ]; then
-		magisk_install_setup
 		case ${MODID} in
 			NanoDroid | NanoDroid_microG )
 				magisk_install_preinst
@@ -539,8 +539,8 @@ magisk_install_finish () {
 		;;
 	esac
 
-	if [ ! -z ${CUSTOM_FONT} ]; then
-		ui_print " << Restore custom font"
+	if [ ! -z ${CUSTOM_FONT} -a -f ${MODPATH}/system/bin/nanodroid-font ]; then
+		ui_print " << Restore NanoDroid-Font (${CUSTOM_FONT})"
 		${MODPATH}/system/bin/nanodroid-font -s "${CUSTOM_FONT}"
 	fi