AccessControl: Enable RBAC by default (#48813)

* Add RBAC section to settings

* Default to RBAC enabled settings to true

* Update tests to respect RBAC

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

pkg/api/frontendsettings.go

@@ -105,6 +105,7 @@ func (hs *HTTPServer) getFrontendSettingsMap(c *models.ReqContext) (map[string]i
 		"autoAssignOrg":                       setting.AutoAssignOrg,
 		"verifyEmailEnabled":                  setting.VerifyEmailEnabled,
 		"sigV4AuthEnabled":                    setting.SigV4AuthEnabled,
+		"rbacEnabled":                         hs.Cfg.RBACEnabled,
 		"exploreEnabled":                      setting.ExploreEnabled,
 		"helpEnabled":                         setting.HelpEnabled,
 		"profileEnabled":                      setting.ProfileEnabled,