Fix PackedCandidate covariance issue

[weishi10141993]

This was done in 92X, now do PR to the master: #20105

[cmsbuild]

A new Pull Request was created by @weishi10141993 for master.

It involves the following packages:

PhysicsTools/PatAlgos

@perrotta, @cmsbuild, @monttj, @slava77 can you please review it and eventually sign? Thanks.
@TaiSakuma, @gouskos, @imarches, @ahinzmann, @acaudron, @mmarionncern, @rappoccio, @jdolen, @nhanvtran, @gpetruc, @gkasieczka, @schoef, @ferencek, @mverzett, @mariadalfonso, @pvmulder, @seemasharmafnal, @JyothsnaKomaragiri this is something you requested to watch as well.
@davidlange6, @slava77 you are the release manager for this.

cms-bot commands are listed here

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/PR-20197/183

Code check has found code style and quality issues which could be resolved by applying a patch in https://cmssdt.cern.ch/SDT/code-checks/PR-20197/183/git-diff.patch
e.g. curl https://cmssdt.cern.ch/SDT/code-checks/PR-20197/183/git-diff.patch | patch -p1

In future, you can run scram build code-checks to apply code checks

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/22364/console Started: 2017/08/17 17:00

[cmsbuild]

+1
Tested at: 13659db
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20197/22364/summary.html

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:
5506301
You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20197/22364/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20197/22364/git-merge-result

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20197/22364/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 26
• DQMHistoTests: Total histograms compared: 2653169
• DQMHistoTests: Total failures: 218
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2652762
• DQMHistoTests: Total skipped: 189
• DQMHistoTests: Total Missing objects: 0
• Checked 107 log files, 14 edm output root files, 26 DQM output files

[perrotta]

+1

• Already evaluated in 92X as Update TrackAndVertexUnpacker.cc #20114
• Changes look reasonable
• Reco sequences not affected: the modified class only enters some test config in the pat area
• No changes expected in reco objects, no changes observed in jenkins tests outputs

[davidlange6]

merge