ANDROID: GKI: update the ABI xml and pixel symbol list

These symbols are used by Pixel 6 on 5.15.

Leaf changes summary: 2 artifacts changed
Changed leaf types summary: 0 leaf type changed
Removed/Changed/Added functions summary: 0 Removed, 0 Changed, 2 Added functions
Removed/Changed/Added variables summary: 0 Removed, 0 Changed, 0 Added variable

2 Added functions:

  [A] 'function int usb_gadget_activate(usb_gadget*)'
  [A] 'function int usb_gadget_deactivate(usb_gadget*)'

Bug: 242746605
Signed-off-by: Will McVicker <willmcvicker@google.com>
Change-Id: I009f3d90cb88cb15c229df31a331c50c0c918c0d