InputTracer: Add timestamp to perfetto trace packets

Use the event processing time as the packet timestamp for input events,
and use the delivery time as the packet timestamp for dispatch events.

Bug: 332714237
Bug: 210460522
Test: atest inputflinger_tests
Test: manual with perfetto
Change-Id: I30f4c21dfee68603d0dad01d205f8a5581e6db31