[PointerLockOnAndroid] Add User gesture checks & handle ESC key

Changes:
- Add User gesture checks when requesting pointer lock, similar to the
ones present in the exclusive_access/pointer_lock_controller.cc
- Handle the `ESC` keydown event to release the pointer lock, diagram
for the key event flow
https://services.google.com/fh/files/misc/keyboard_esc_event_flow.png.

Bug: 416429837
Change-Id: I139000a2309900d6038bb15d2c7466bc181db087
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6519718
Reviewed-by: Bartosz Chomiński <chominskib@google.com>
Commit-Queue: Abdelrahman Eed <abdoeed@google.com>
Reviewed-by: Olga Korokhina <korokhina@google.com>
Cr-Commit-Position: refs/heads/main@{#1461254}