High latency for response message (>=248 bytes)

## Bug Report

### Version

├── tonic v0.5.2
└── tonic-build v0.5.2
### Platform

Unix:
Linux 4.18.0-305.10.2.el8_4.x86_64 SMP Tue Jul 20 17:25:16 UTC 2021 x86_64 GNU/Linux

MacOs:
Darwin XXX-MacBook-Pro.local 21.6.0 Darwin Kernel Version 21.6.0: Mon Aug 22 20:17:10 PDT 2022; root:xnu-8020.140.49~2/RELEASE_X86_64 x86_64

### Description

Code: https://github.com/Jerrykl/tonic-example

I observe a curious phenomenon that when the size of gRPC message response is greater or equal than 248 bytes, the RPC latency would jump to 43~44 ms. Howerver, when the message is less than 247 bytes the latency is almost less than 1ms.

I have also tested on my MacBook but the latency stays low for both 247 bytes' and 248 bytes' message.