[Accessibility] Narrator should announce "end of line'" instead of "Space" when focusing on last text position in comboBox and textBox

[Olina-Zhang]

• .NET Core Version:
  .Net 6.0 SDK build: 6.0.100-Preview.4.21180.17

• Have you experienced this same bug with .NET Framework?:
  No

• More Info
  This is a regression issue, found after the fix of PR: Adding support for text pattern to ComboBox #4540

Repro Steps:

1. Open attached application in VS, build and run it
   WinFormsApp11.zip
2. Open Narrator to focus the last position of item in comboBox and TextBox
   for comboBox, use mouse expand dropdown list, choose any of item, then move mouse to last position in edit part
   for textBox, from other control tab to textBox, then move mouse to last position in edit part
   Actual behavior:
   Narrator announces "end of line" when moving mouse to last position in edit of comboBox and textBox
   
   

Expected behavior:
Narrator should announce "end of line" when moving mouse to last position in edit of comboBox and textBox

[SergeySmirnov-Akvelon]

This regression is the result of adding text pattern support (#2701) to the TextBox. This issue is reproducible for the ComboBox, because we reused the same logic to support the text pattern (#4540)

[SergeySmirnov-Akvelon]

Since this case is not common and it takes a lot of time to investigate the causes and fix it, we close it as "won't fix". If a customer asks for a fix, we will reopen it.