Update xtrabackup package name for Ubuntu 20.04

[rsynnest]

Percona no longer includes the generic package name 'percona-xtrabackup' in their Ubuntu 20.04 focal fossa release of percona-xtrabackup. The package name 'percona-xtrabackup-24' must be used instead. This can be verified in the package names included by percona-release, listed at https://repo.percona.com/apt/dists/focal/main/binary-amd64/Packages

[CLAassistant]

All committers have signed the CLA.

[puppet-community-rangefinder]

mysql::params is a class

Breaking changes to this file WILL impact these 2 modules (exact match):

• brucem-ezpublish
• edestecd-mariadb

Breaking changes to this file MAY impact these 1 modules (near match):

• willdurand-bazinga

This module is declared in 143 of 576 indexed public Puppetfiles.

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These results were generated with Rangefinder, a tool that helps predict the downstream impact of breaking changes to elements used in Puppet modules. You can run this on the command line to get a full report.

Exact matches are those that we can positively identify via namespace and the declaring modules' metadata. Non-namespaced items, such as Puppet 3.x functions, will always be reported as near matches only.

[pmcmaw]

@rsynnest I would like to thank you for your PR. :-)
Ubuntu20.04 test failures seen are unrelated to this PR therefore I am going to merge.

Known failures on Ubunutu20.04 are being tracked here: https://tickets.puppetlabs.com/browse/IAC-1612