Create a timerfd JNI class

The timerfd delivers timer expiration notifications via a file
descriptor, which can be used to implement delayed callbacks.
Create a JNI class to interface with the timerfd system calls.

Bug: 366373064
Test: m
Change-Id: I0ae7a4cf618838e614b2fa4523b55a4d0e8f74e2
4 files changed