fix(kuma-cp): reset idleTimeout from the old Timeout policy

[lobkovilya]

Checklist prior to review

• Link to relevant issue as well as docs and UI issues -- IdleTimeout on httpConnectionManager is set from Timeout policy even though MeshTimeout is defined #6644
• This will not break child repos: it doesn't hardcode values (.e.g "kumahq" as a image registry) and it will work on Windows, system specific functions like syscall.Mkfifo have equivalent implementation on the other OS --
• Tests (Unit test, E2E tests, manual test on universal and k8s) --
• Do you need to update UPGRADE.md? --
• Does it need to be backported according to the backporting policy? --
• Do you need to explicitly set a > Changelog: entry here or add a ci/ label to run fewer/more tests?

[michaelbeaumont]

Can we add a test that shows the interaction between both policies to show the fix?