Replace ShortcutType with UserShortcutType to reduce duplicate
declaration.

- Replace AccessibilityManager.ACCESSIBILITY_BUTTON with
  ShortcutConstants.UserShortcutType.SOFTWARE
- Replace AccessibilityManager.ACCESSIBILITY_SHORTCUT_KEY with
  ShortcutConstants.UserShortcutType.HARDWARE

Bug: 323686675
Test: atest
Flag: N/A. Not able to flag the refactor
Change-Id: I2085f5307122ad3252d4ca396666780c3d6e9ce1
24 files changed