metropolis: add Reboot RPC

This adds a new Reboot RPC to reboot a running node. It also supports
rebooting into the passive slot and powering off the node.

Change-Id: I329b22ea879adeb65a3e31103d39ad89813d61e8
Reviewed-on: https://review.monogon.dev/c/monogon/+/3354
Tested-by: Jenkins CI
Reviewed-by: Leopold Schabel <leo@monogon.tech>
diff --git a/metropolis/proto/ext/authorization.proto b/metropolis/proto/ext/authorization.proto
index 4c27f3e..e526ec3 100644
--- a/metropolis/proto/ext/authorization.proto
+++ b/metropolis/proto/ext/authorization.proto
@@ -29,6 +29,7 @@
     PERMISSION_DECOMMISSION_NODE = 8;
     PERMISSION_DELETE_NODE = 9;
     PERMISSION_UPDATE_NODE_LABELS = 10;
+    PERMISSION_NODE_POWER_MANAGEMENT = 11;
 }
 
 // Authorization policy for an RPC method. This message/API does not have the