Initialize the SodaInstaller only once

Currently the SodaInstaller is initialized twice: once by chrome/browser/chrome_browser_main.cc and once by chrome/browser/accessibility/caption_controller.cc. Because the SodaInstaller is used by multiple features that use the Speech On-Device API (SODA), the SodaInstaller should check to ensure that the SODA components are only registered once. Registering a component multiple times is not necessarily problematic, but it results in unnecessary overehead.

Bug: 1207705
Change-Id: If091ad1722f2d4b9ee6f907d444117b491f1f01e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2885203
Reviewed-by: Abigail Klein <abigailbklein@google.com>
Commit-Queue: Evan Liu <evliu@google.com>
Cr-Commit-Position: refs/heads/master@{#881726}