add rmt_storage to "shutdown critical"

- should be kept to write modem data befure shutdown.

bug: 37626581
Test: build only

Change-Id: I23d127452f680f5cd52430e8d5580d08b66ba009
diff --git a/init.angler.rc b/init.angler.rc
index 775344a..399f61e 100755
--- a/init.angler.rc
+++ b/init.angler.rc
@@ -339,6 +339,7 @@
     user root
     group system wakelock
     writepid /dev/cpuset/system-background/tasks
+    shutdown critical
 
 service qseecomd /vendor/bin/qseecomd
     class core