[Read Aloud] Fix emoji infinite loop.

Bug: 332897618
Change-Id: Ic5451ee68a3f91eb9d7c10d56441035ca062ff0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5426223


Commit-Queue: Lauren Winston <lwinston@google.com>
Reviewed-by: Kristi Saney <kristislee@google.com>
Cr-Commit-Position: refs/heads/main@{#1282781}