Synthesize cancellation events when device is disabled

When disable a keyboard device, if some keys still stay in down, we
should synthesize the cancellation events for these keys to prevent the
states can't be reset when they're handled by policy or client side.

Bug: 239888702
Test: atest inputflinger_tests
Change-Id: I8d73d5b2b3df81d047799cb7e9403f170a094f97