Undo some CLI flag breakages (#5902)

* Undo some CLI breakages

* Update CLI book docs

lighthouse/tests/beacon_node.rs

@@ -2178,6 +2178,21 @@ fn slasher_broadcast_flag_no_default() {
         });
 }
 #[test]
+fn slasher_broadcast_flag_no_argument() {
+    CommandLineTest::new()
+        .flag("slasher", None)
+        .flag("slasher-max-db-size", Some("1"))
+        .flag("slasher-broadcast", None)
+        .run_with_zero_port()
+        .with_config(|config| {
+            let slasher_config = config
+                .slasher
+                .as_ref()
+                .expect("Unable to parse Slasher config");
+            assert!(slasher_config.broadcast);
+        });
+}
+#[test]
 fn slasher_broadcast_flag_true() {
     CommandLineTest::new()
         .flag("slasher", None)

lighthouse/tests/validator_client.rs

@@ -593,7 +593,7 @@ fn wrong_broadcast_flag() {
 }
 
 #[test]
-fn latency_measurement_service() {
+fn disable_latency_measurement_service() {
     CommandLineTest::new()
         .flag("disable-latency-measurement-service", None)
         .run()
@@ -601,6 +601,16 @@ fn latency_measurement_service() {
             assert!(!config.enable_latency_measurement_service);
         });
 }
+#[test]
+fn latency_measurement_service() {
+    // This flag is DEPRECATED so has no effect, but should still be accepted.
+    CommandLineTest::new()
+        .flag("latency-measurement-service", Some("false"))
+        .run()
+        .with_config(|config| {
+            assert!(config.enable_latency_measurement_service);
+        });
+}
 
 #[test]
 fn validator_registration_batch_size() {