Injecting User role for background job

[saratvemulapalli]

*Issue #195 *

Description of changes:
Adding User role injection to AD background job runner

The changes are manually tested on a test domain.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

Merging #295 into master will decrease coverage by 0.09%.
The diff coverage is 57.14%.

@@             Coverage Diff              @@
##             master     #295      +/-   ##
============================================
- Coverage     71.16%   71.06%   -0.10%     
+ Complexity     1874     1873       -1     
============================================
  Files           195      195              
  Lines          9056     9063       +7     
  Branches        765      766       +1     
============================================
- Hits           6445     6441       -4     
- Misses         2245     2255      +10     
- Partials        366      367       +1     

Flag	Coverage Δ	Complexity Δ
#cli	79.27% <ø> (ø)	0.00 <ø> (ø)
#plugin	70.36% <57.14%> (-0.11%)	1873.00 <0.00> (-1.00)

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Impacted Files	Coverage Δ	Complexity Δ
...oforelasticsearch/ad/AnomalyDetectorJobRunner.java	75.00% <57.14%> (-0.64%)	36.00 <0.00> (ø)
...port/SearchAnomalyDetectorInfoTransportAction.java	54.54% <0.00%> (-9.10%)	4.00% <0.00%> (ø%)
...ransport/DeleteAnomalyDetectorTransportAction.java	53.40% <0.00%> (-4.55%)	15.00% <0.00%> (-1.00%)

[kaituo]

Looks good. Build is failing.

[saratvemulapalli]

Looks good. Build is failing.

Thanks Kaituo for taking a look.
Fixed the tests as well.