Don't set mFdEvents if looper fd update fails

While it should not happen in practice, it's possible that adding or
removing the fd from the message queue's looper could fail. Setting
`mFdEvents` to `events` in this case can cause the event receiver and
the looper to go out of sync.

If either the add or remove operations return -1, skip the update so
that we at least remain consistent, albiet in a bad state.

Bug: 416266715
Test: atest InputEventSenderAndReceiverTest
Flag: EXEMPT bugfix
Change-Id: I069f7269e563aff2abf62598200f5275c2e612a4