[7.x] elasticsearch: add known unhandled libbeat config (#3800)

[axw]

Backports the following commits to 7.x:

• elasticsearch: add known unhandled libbeat config (elasticsearch: add known unhandled libbeat config to test #3800)

[codecov-commenter]

Codecov Report

Merging #3804 into 7.x will increase coverage by 0.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##              7.x    #3804      +/-   ##
==========================================
+ Coverage   79.74%   79.83%   +0.08%     
==========================================
  Files         136      136              
  Lines        6158     6158              
==========================================
+ Hits         4911     4916       +5     
+ Misses       1247     1242       -5     

Impacted Files	Coverage Δ
kibana/connecting_client.go	72.58% <0.00%> (+8.06%)	⬆️

[apmmachine]

💚 Build Succeeded

Expand to view the summary

Build stats

• Build Cause: [Pull request [7.x] elasticsearch: add known unhandled libbeat config (#3800) #3804 opened]

• Start Time: 2020-05-19T04:04:36.641+0000

• Duration: 27 min 58 sec (1617851)

Test stats 🧪

Test	Results
Failed	0
Passed	3014
Skipped	142
Total	3156