uinput: Specify timestamps when injecting events from evemu

Last year support for specifying timestamps for uinput events was added
to the Linux Kernel [0]. This allows us to give precise timestamps for
events being played back from an evemu recording, despite the actual
times at which we inject them being imprecise due to how threads and
the kernel are scheduled.

[0]: https://lore.kernel.org/lkml/20230427000152.1407471-1-biswarupp@google.com/

Bug: 310958309
Test: with the patch added to the device's kernel, play back pointing
      stick and touchscreen recordings. Compare `getevent -lt` output
      with the timestamps in the recordings to check that the offsets
      between timestamps match (e.g. using a spreadsheet).
Test: atest UinputTests
Change-Id: If486cdb7218918aca64e6561f9fc2f30acce736a