Add labels and permissions for /mnt/vm

It will be used as a storage for early boot virtmgr.

Bug: 354059281
Test: boot and check /early-vm
Change-Id: Ida44cdb3de3a42daf210cc2c4100615e6aab77e3
diff --git a/private/dumpstate.te b/private/dumpstate.te
index 20341e4..13b7b9f 100644
--- a/private/dumpstate.te
+++ b/private/dumpstate.te
@@ -537,6 +537,7 @@
   linkerconfig_file
   mirror_data_file
   mnt_user_file
+  vm_data_file
 }:dir getattr;
 
 # Allow dumpstate to talk to bufferhubd over binder