Update Speech Recognition Sandbox on Linux

This CL updates the Speech Recognition sandbox on Linux by allowing the prctl syscall.

On 11/09, SODA version 1.1.1.8 began rolling out to Linux clients. Almost immediately crash reports with sandbox::SIGSYSPrctlFailure in the callstack began flooding in, suggesting that the new version issued the prctl syscall that is not allowed by the sandbox.

Fix: 379059526
Change-Id: I037a94a0cec5389bb79afe68bbd656ce2e3fb748
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6036167
Commit-Queue: Evan Liu <evliu@google.com>
Reviewed-by: Matthew Denton <mpdenton@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1385870}