Revert "Reland "Fix VoiceOver bug when reading the first child of a content editable.""

This reverts commit 7bfad53e655827061fe685d300da83ebc9b2c119.

Reason for revert: Breaks accessibility for contenteditable elements
in sites such as gmail. Chrome reports contenteditable fields as groups (role "AXGroup") instead of text areas (role "AXTextArea"). This causes VoiceOver to incorrectly read out a text area as a group. In addition to that it also seems to break integration with other tools like Grammarly for macOS.

This change is a clean revert, aside from a rebaseline of a test that was previously disabled. You can view this diff in patchset 3

Original change's description:
> Reland "Fix VoiceOver bug when reading the first child of a content editable."
>
> This is a reland of commit 0838899b152eea4c3c4bb0a97cf83b24bd66c535
>
> The original CL was reverted due to a test failure, the expected text needed updating from AXTextArea to AXGroup. This issue has been fixed by modifying the expected text. Have verified in job "mac_chromium_10.15_rel_ng".
>
> Original change's description:
> > Fix VoiceOver bug when reading the first child of a content editable.
> >
> > Recently, we encountered an issue where the first element inside a <div contenteditable=true> was not narrated by VoiceOver. As we were sending the appropriate notifications and native node to the system. The problem was traced to the contenteditable <div>, which was classified as a kgenericContainer type. Initially, its role was set to "TextArea", which led to the narration issue. By changing its role from "TextArea" to "Group", we aligned its behavior with that of Safari. This modification ensured that VoiceOver could correctly narrate the first element inside the <div>.
> >
> > AX-Relnotes:Changed the role of contenteditable div from "TextArea" to "Group". This improves the behavior of VoiceOver by allowing it to narrate the first element within the div more accurately. Users who rely on VoiceOver for navigating contenteditable areas will benefit from improved accessibility and narration precision.
> >
> > Bug: 344606394
> >
> > Change-Id: Ie99423b04708741fbac94a9ca9c779909314f009
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5644580
> > Reviewed-by: Jacques Newman <janewman@microsoft.com>
> > Reviewed-by: Leon Han <shulianghan@microsoft.com>
> > Commit-Queue: yan libang <libangyan@microsoft.com>
> > Cr-Commit-Position: refs/heads/main@{#1322558}
>
> Bug: 344606394
> Change-Id: I2ef68d086cc9236db4c641bea43f9c5a6f81d4ff
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5667445
> Reviewed-by: Nektarios Paisios <nektar@chromium.org>
> Reviewed-by: Jacques Newman <janewman@microsoft.com>
> Commit-Queue: yan libang <libangyan@microsoft.com>
> Cr-Commit-Position: refs/heads/main@{#1333341}

Bug: 344606394, 370009398
Change-Id: I2437e0bf0e2808cdc9364b48fb6c686c4e2b58e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5900532
Reviewed-by: Benjamin Beaudry <benjamin.beaudry@microsoft.com>
Reviewed-by: Shuliang Han <leonhsl@chromium.org>
Commit-Queue: Jacques Newman <janewman@microsoft.com>
Reviewed-by: Leon Han <shulianghan@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1363251}