Revert "[JTC] Remove read_only from 'joints', 'state_interfaces' and …

…'command_interfaces' parameters (#967)" (#978)

This reverts commit 6e2736b.

(cherry picked from commit 9f7e9e9)

joint_trajectory_controller/src/joint_trajectory_controller_parameters.yaml

@@ -3,6 +3,7 @@ joint_trajectory_controller:
     type: string_array,
     default_value: [],
     description: "Names of joints used by the controller",
+    read_only: true,
     validation: {
       unique<>: null,
     }
@@ -20,6 +21,7 @@ joint_trajectory_controller:
     type: string_array,
     default_value: [],
     description: "Names of command interfaces to claim",
+    read_only: true,
     validation: {
       unique<>: null,
       subset_of<>: [["position", "velocity", "acceleration", "effort",]],
@@ -30,6 +32,7 @@ joint_trajectory_controller:
     type: string_array,
     default_value: [],
     description: "Names of state interfaces to claim",
+    read_only: true,
     validation: {
       unique<>: null,
       subset_of<>: [["position", "velocity", "acceleration",]],