Extracting vmId form Azure instance metadata

[FabianMeiswinkel]

Description

Extracts the vmId from Azure instance metadata and put the vmId (or a static UUID for the lifetime of the process) as static machine identifier into the request diagnostics and client telemetry. I have used a static uuid instead of trying to get the machine name (and hash it for PII reasons) because there is no reliable way to get the host name in java (it either maps to OS specific implementations or is using network calls with revers-DNS lookup). All we need is a stable identifer - stable even across multiple cosmos client instances if customers don't use singleton pattern - that we can also use to distinguish client machines. The vmId is ideal because with Client Telemetry it would allow us to get further telemetry - like OS metrics etc. if the customer's app is hosted on Azure(and instance metadata is available). When vmId isn't availbel a stable identifier is the min-bar.

NOTE: I also fixed a typo in the package name for client telemetry - this is internal API - so shouldn't be breaking

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[FabianMeiswinkel]

Fixes #27689

[kushagraThapar]

Sorry, but I am still confused between machineId and vmId . Can't we choose a consistent name or is that intentional to keep them separate?

[xinlian12]

LGTM, thanks

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[sourabh1007]

A sample Request diagnostics and client telemetry payload after this change would be really helpful.