[8.6](backport #2172) Accept fleet.proxy_url policy options

[mergify]

This is an automatic backport of pull request #2172 done by Mergify.

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• Start Time: 2023-01-25T15:13:04.142+0000

• Duration: 18 min 22 sec

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Test	Results
Failed	0
Passed	4845
Skipped	13
Total	4858

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🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	98.305% (58/59)	👍
Files	69.268% (142/205)	👍
Classes	69.231% (270/390)	👍
Methods	54.047% (828/1532)	👍
Lines	39.272% (9044/23029)	👎 -0.013
Conditionals	100.0% (0/0)	💚