Eng tracking bug for crbug/757077 - Haven-based integrated security key support

This is simply raising a notification that the power button will behave differently during a security key request:
https://docs.google.com/presentation/d/1hE_U-hUqj4fU-_p52SAn4cVSv5NhDfLLZGjVnq8JFYY/edit#slide=id.g2f053bdfea_0_0