Reland "[UIA] Don't fire UIA_TextChangedEvents when text attributes change"

This is a reland of commit 38893242692ad5a284dd393d436a8f3d5b46da7f

I removed the expectation file for IA2 on Windows - the expectations
do not always match over there. Since this change is only about UIA,
it shouldn't really matter.

Original change's description:
> [UIA] Don't fire UIA_TextChangedEvents when text attributes change
>
> On UIA, we shouldn't be firing UIA_TextChangedEvents when a text attribute
> changes. Prior to this CL, an update to any of the following text attributes
> would have fired a text changed event:
>
> - Font-size
> - Font-weight
> - Font-family
> - Background-color
> - Color
> - Text-direction
> - Text-position
> - Text-style
> - Text-overline-style
> - Text-strikethrough-style
> - Text-underline-style
>
> Not anymore.
>
> Change-Id: I6c4fbfd47fe6f530b8700ca709c3dcfe355c67bc
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3722757
> Reviewed-by: Nektarios Paisios <nektar@chromium.org>
> Reviewed-by: Jacques Newman <janewman@microsoft.com>
> Commit-Queue: Benjamin Beaudry <benjamin.beaudry@microsoft.com>
> Cr-Commit-Position: refs/heads/main@{#1022368}

R=nektar@chromium.org,janewman@microsoft.com

Change-Id: Ie8a9aaba213a92b787b24f06d5270c8c7d9edad5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3756183
Reviewed-by: Jacques Newman <janewman@microsoft.com>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Benjamin Beaudry <benjamin.beaudry@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1022880}