util/syspolicy: add policy counters (#10471)

Fixes tailscale/corp#16138

Signed-off-by: Claire Wang <claire@tailscale.com>

util/syspolicy/policy_keys.go

@@ -50,3 +50,33 @@ const (
 	// The default is "user-decides" unless otherwise stated.
 	PostureChecking Key = "PostureChecking"
 )
+
+var stringKeys = []Key{
+	ControlURL,
+	LogTarget,
+	Tailnet,
+	ExitNodeID,
+	ExitNodeIP,
+	EnableIncomingConnections,
+	EnableServerMode,
+	ExitNodeAllowLANAccess,
+	EnableTailscaleDNS,
+	EnableTailscaleSubnets,
+	AdminConsoleVisibility,
+	NetworkDevicesVisibility,
+	TestMenuVisibility,
+	UpdateMenuVisibility,
+	RunExitNodeVisibility,
+	PreferencesMenuVisibility,
+	ExitNodeMenuVisibility,
+	AutoUpdateVisibility,
+	KeyExpirationNoticeTime,
+	PostureChecking,
+}
+
+var boolKeys = []Key{
+	LogSCMInteractions,
+	FlushDNSOnSessionUnlock,
+}
+
+var uint64Keys = []Key{}