Cherry-pick #18350 to 7.8: Pick up version from libbeat

[michalpristas]

Cherry-pick of PR #18350 to 7.8 branch. Original message:

What does this PR do?

For historical reasons we were keeping track of our version ourselves which creates overhead for releases. Picking up version from libbeat keeps us in par with other beats we're releasing with

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[elasticmachine]

💚 Build Succeeded

Expand to view the summary

Build stats

• Build Cause: [Pull request Cherry-pick #18350 to 7.8: Pick up version from libbeat  #18578 updated]

• Start Time: 2020-05-18T06:04:00.333+0000

• Duration: 32 min 30 sec (1949878)

[blakerouse]

Backport looks good.