Summary:
Because it is possible to change the root install directory on a rehydration,
yba-installer will set the config to enable path fixup.

Also fixed a bug with the prometheus log file symlink

Test Plan: os rehydration with upgrade + root install change.

Reviewers: muthu, sanketh

Reviewed By: muthu

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D38962