Add metrics for HMSS mill.

[renjiezh]

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This change is 

[ple13]

Reviewed 2 of 2 files at r1, all commit messages.
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[SanjayVas]

Would you mind rebasing this on #1623 ? That makes significant changes to how we do metrics.

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[renjiezh]

I will sync with that PR once it is merged. Thanks!

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[SanjayVas]

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src/main/kotlin/org/wfanet/measurement/duchy/daemon/mill/shareshuffle/HonestMajorityShareShuffleMill.kt line 451 at r2 (raw file):

    logWallClockDuration(
      token,
      DATA_TRANSMISSION_WALL_CLOCK_DURATION,

nit: this is not technically data transmission time but rather RPC time, of which data transmission is a component. This includes whatever processing the server is doing for this call.

[ple13]

Reviewed 2 of 2 files at r2, all commit messages.
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[stevenwarejones]

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[renjiezh]

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Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @renjiezh)