[main] moe(perf): Refactor GDN A2A helper flow

[yuzhongw-nvidia]

• I, the PR author, have personally reviewed every line of this PR.

What does this PR do ?

PR for dev: #5389

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[yuzhongw-nvidia]

/ok to test f3e33f2

[xuantengh]

LGTM, thanks!

[yuzhongw-nvidia]

/ok to test a19a172

[kvareddy]

@Mellonta can you please take a look at this MR?

[Mellonta]

LGTM

[yuzhongw-nvidia]

/ok to test 95ae9f8