Cherry-pick #18814 to 7.x: Fix install service script for windows

[michalpristas]

Cherry-pick of PR #18814 to 7.x branch. Original message:

What does this PR do?

Agent was using beat version of install service script for windows but the way how agent is started is different.
This PR aligns script with the agent command syntax

Why is it important?

To enable agent be installed on windows as a service

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.

Fixes: #18811

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• Build Cause: [Started by user Michal Pristas, Replayed #1]

• Start Time: 2020-05-29T11:24:06.221+0000

• Duration: 78 min 31 sec

Test stats 🧪

Test	Results
Failed	0
Passed	6648
Skipped	1053
Total	7701