[Rollout UI] Changing to a phase with the same population percentage returns a RS rejection after approval

[data-sync-user]

[Prerequisites]:

• Have a new android or iOS rollout filled with valid data.
• Have 2 phases with the same population percentage configured.

[Steps to reproduce]:

1. Have someone else click the "Start next phase" button.
2. Click the "Approve" button and click the "Open remote settings" button.
3. Approve the RS change and observe the rollout's page.

[Expected result]:

• The rollout changes to the next phase from the schedule.

[Actual result]:

• The rollout remains in the original phase and the "Rejected from Remote Settings" error is displayed.

[Notes]:

• Attached a screen recording of the issue:

┆Issue is synchronized with this Jira Task