Do not apply mtectrl state on shutdown if it hadn't been loaded

This would reset the MTE state for incomplete boots

Test: MemtagBootctlTest

Change-Id: I2b5f2afd55ea85fa59a11baa79e2c96b07897da6

Author: fmayer

mtectrl/mtectrl.rc

@@ -25,7 +25,7 @@ on property:persist.device_config.runtime_native_boot.bootloader_override=* && p
 on early-boot && property:ro.arm64.memtag.bootctl_supported=1
   exec_background -- /system/bin/mtectrl -s arm64.memtag.bootctl -f arm64.memtag.bootctl_loaded
 
-on shutdown && property:ro.arm64.memtag.bootctl_supported=1
+on shutdown && property:ro.arm64.memtag.bootctl_supported=1 && property:arm64.memtag.bootctl_loaded=*
   # This doesn't use wait_for_prop to not stall the shutdown.
   exec -- /system/bin/mtectrl ${arm64.memtag.bootctl:-none} ${persist.device_config.runtime_native_boot.bootloader_override:-default}