Fix unsafe buffer usage in AdbClientSocket

Replaced an unsafe `reinterpret_cast` that was used to extract bytes from a size_t with a safe, portable bit-shifting approach. This avoids dependence on host machine endianness.

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Bug: 435317390
Bug: 435681993
Fixed: 435681993
Change-Id: I1079609c05ecebfbf126cd5443eacd67cdcb9b2e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6811277
Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: David Roger <droger@chromium.org>
Auto-Submit: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1524177}