Backend: fix byname finding on modern Android versions for devices without super

- /dev/block/mapper exists on all devices with apex but only contains system partition symlinks on devices with super partition logical partitions

META-INF/com/google/android/update-binary

@@ -131,7 +131,7 @@ mount_all() {
   fi;
   byname=bootdevice/by-name;
   [ -d /dev/block/$byname ] || byname=$($BB find /dev/block/platform -type d -name by-name 2>/dev/null | $BB head -n1 | $BB cut -d/ -f4-);
-  [ -d /dev/block/mapper ] && byname=mapper;
+  [ -e /dev/block/$byname/super ] && [ -d /dev/block/mapper ] && byname=mapper;
   [ -e /dev/block/$byname/system ] || slot=$(find_slot);
   case $ANDROID_ROOT in
     /system_root) setup_mountpoint /system;;

META-INF/com/google/android/updater-script

@@ -3,4 +3,4 @@
 # Dummy file; update-binary is a shell script (DO NOT CHANGE)
 #
 #
-# AK_BASE_VERSION=20230323
+# AK_BASE_VERSION=20230405