Add possibility to upload release notes in promote task

[SWarnberg]

In a release workflow you often promote a release after many versions has been tested in a previous stage. Hence, the release notes when promoting a release is different from the latest release you're promoting. Therefore, please add ability to update the release notes in the promote task.

As a background, when using release stages, each stage can automatically generate unique release notes based on the previously approved release. For instance by using the GenerateReleaseNotes task.

[rvlente]

I would also really like this feature. Currently, I have to manually update the release notes for 10+ apps before promoting to the production track for every release.

[dovd-chabad]

When promoting the latest build from a track, the release notes are copied from that track. But if I want to make sure to promote a specific version code from the source track, the release notes are NOT copied and I can't find a way to independently update the target track release notes.

Adding this feature would solve the above problem and also allow me to edit the release notes during the promote task.