[FIX] test_main_flows: fix main flow on Mobile (on changing month)

On mobile, when tours are run on changing month, the "Register Payment"
step often fails with the following error:
AssertionError: The test code "odoo.startTour('main_flow_tour')" failed
Tour main_flow_tour failed at step Register Payment (trigger:
.o_statusbar_buttons button:enabled:contains('Register Payment'))

Please note before going further:
* The main flow is a tour. The tour manager waits for the trigger and
  the extra trigger to be reachable before executing the step.
* On mobile the status bar buttons are wrapped in a dropdown.
  So the stepUtils.statusbarButtonsSteps is composed by two actions:
  1 - Open the dropdown if present.
  2 - Click on the button.

Before this commit, the extra trigger doesn't look like the best one:
when this tour is executed during month change, the account
module has to perform some heavier (and longer) processes.
When the "Validate" call button is made (previous step), a lot of RPC
are made and, usually, the previous extra trigger works fine.
But for some reasons, the _renderStatusbarButtons is called
between the two steps in the statusbarButtonsSteps.

So this is the flow:
- Running the tour until...
- Click "Validate" button (this generates a bunch of RPC).
- Open the dropdown.
- Some RPC respond, which refresh the "state" and call _renderStatusbarButtons
  (dropdown is not open anymore).
- Try to click on "Register Payment" => BUG
  (button is present but not visible, so unreachable).

After this commit, the extra trigger is changed to force waiting for
the RPC that change the "state" and call _renderStatusbarButtons
before executing the "Register Payment" step.

closes odoo/odoo#61085

X-original-commit: dacc1703c486c8affb44df679ab5e8e2ba724867
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>
Signed-off-by: rfr-odoo <rfr-odoo@users.noreply.github.com>

odoo/addons/test_main_flows/static/tests/tours/main_flow.js

@@ -941,7 +941,7 @@ tour.stepUtils.mobileModifier(tour.stepUtils.autoExpandMoreButtons('.o_control_p
     position: "bottom",
 },
 ...tour.stepUtils.statusbarButtonsSteps('Confirm', _t("Validate"), ".breadcrumb-item.active:contains('Draft Invoice')"),
-...tour.stepUtils.statusbarButtonsSteps('Register Payment', _t("Register Payment"), ".breadcrumb-item.active:contains('INV/')"),
+...tour.stepUtils.statusbarButtonsSteps('Register Payment', _t("Register Payment"), ".o_statusbar_status .btn.dropdown-toggle:contains('Posted')"),
 {
     trigger: ".modal-footer .btn-primary",
     content: _t("Validate"),