[backport#17261 7/13] Make UpgradeKeyMetadata work only on LegacyScriptPubKeyMan

Summary:
https://github.com/bitcoin/bitcoin/pull/17261/commits/01b4511206e399981a77976deb15785d18db46ae

Depends on D7851

Partial backport of Core PR17261

Test Plan:

ninja all check check-functional

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D7854