Pass IDLE to on_tick, use that for initialize condition

[redvinaa]

Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#3988
Primary OS tested on	(Ubuntu, MacOS, Windows)
Robotic platform tested on	–
Does this PR contain AI generated software?	No

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Description of contribution in a few bullet points

• Pass IDLE state to BT action nodes (to the on_tick callback), and use that as initialize condition
• This way ports can be updated at every restart (on first start and after each halt)
• See conversation at the bottom of BT nodes not able to accept parameter values #3988

For Maintainers:

• Check that any new parameters added are updated in docs.nav2.org
• Check that any significant change is added to the migration guide
• Check that any new features OR changes to existing behaviors are reflected in the tuning guide
• Check that any new functions have Doxygen added
• Check that any new features have test coverage
• Check that any new plugins is added to the plugins page
• If BT Node, Additionally: add to BT's XML index of nodes for groot, BT package's readme table, and BT library lists

[SteveMacenski]

I see no issues with this, LGTM once CI passes :-)

Thanks for bringing this to our attention!

[SteveMacenski]

@redvinaa it looks like 1 test is failing (ignore DWB; that's occasionally flaky). It probably just needs a quick update

[redvinaa]

I have no idea why that particular test failed. It's possible that a rerun would solve it.

[SteveMacenski]

I triggered a rebuild, but I don't expect that to change, a unit test like that shouldn't be flaky

[redvinaa]

Found it: the subscriber was always recreated in initialize, and as in the test we spin first and then tick, the callback was always called with the old inputs. Changed initialize to only create new subscriber when the topic has changed (or in the beginning when the sub doesn't exist yet).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
...tree/include/nav2_behavior_tree/bt_action_node.hpp	85.82% <100.00%> (ø)
...ior_tree/plugins/action/assisted_teleop_action.hpp	100.00% <ø> (ø)
...v2_behavior_tree/plugins/action/back_up_action.hpp	100.00% <ø> (ø)
...tree/plugins/action/remove_passed_goals_action.hpp	100.00% <ø> (ø)
.../nav2_behavior_tree/plugins/action/spin_action.hpp	100.00% <ø> (ø)
.../nav2_behavior_tree/plugins/action/wait_action.hpp	100.00% <ø> (ø)
.../plugins/condition/distance_traveled_condition.hpp	100.00% <ø> (ø)
..._tree/plugins/condition/goal_reached_condition.hpp	100.00% <ø> (ø)
...ree/plugins/condition/is_battery_low_condition.hpp	100.00% <ø> (ø)
...tree/plugins/condition/is_path_valid_condition.hpp	100.00% <ø> (ø)
... and 15 more

... and 1 file with indirect coverage changes