Use filestream instead of deprecated log input

[felixbarny]

Relates to elastic/ecs-logging#67

[ghost]

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• Start Time: 2022-08-21T10:31:17.415+0000

• Duration: 7 min 55 sec

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[eyalkoren]

Like we do in step 2 - use both examples for > and <= 7.16

[SylvainJuge]

For reference, this is what it currently looks like with docs for 2 versions:

I wonder if we could make it simpler to have only the most recent version documented, but with 7.16 < option still accessible.