make sure RestrictSystemAdmin returns for all users access system console (#30384)

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/api4/config_test.go

@@ -122,6 +122,7 @@ func TestGetConfigAnyFlagsAccess(t *testing.T) {
 	require.NoError(t, err)
 	t.Run("Can read value with permission", func(t *testing.T) {
 		assert.NotNil(t, cfg.FeatureFlags)
+		assert.NotNil(t, cfg.ExperimentalSettings.RestrictSystemAdmin)
 	})
 }