Restart shutdown_runner in Linux VM on failure

Bug: 395521180
Test: Run VmTerminalApp & sudo systemctl status at Linux VM
Change-Id: I999d152a3bb336aa6ab1fc22a31318eaa1f5b510
diff --git a/guest/shutdown_runner/debian/service b/guest/shutdown_runner/debian/service
index d19ff25..7188d36 100644
--- a/guest/shutdown_runner/debian/service
+++ b/guest/shutdown_runner/debian/service
@@ -6,6 +6,8 @@
 [Service]
 ExecStart=/usr/bin/bash -c '/usr/bin/shutdown_runner --grpc_port $(cat /mnt/internal/debian_service_port)'
 Type=simple
+Restart=on-failure
+RestartSec=1
 User=root
 Group=root