sdp_upgrade.sh v1.3.3:
* Removed command line verification restraint for '-p' due to preview mode being default.
* Changed default log directory from /tmp to ~ (home directory).
* Silence a warning about /p4/metrics (part of P4Prometheus) being ignored.
* If errors and/or warnings occur, display a 'grep' command that can be used to
list them.
* Enhanced error message for failure mode where the SDP upgrade fails due to failure to
backup /p4/common, e.g. due to root-owned files.
* Corrected message related to deprecated file removal.