simpleperf: record cmd: Add --delay option

When the --delay option is used, the record command waits for
the specified period of time before recording samples.

Also, make IOEventLoop use a precise timer by default. This way,
we don't need to set it in places that use IOEventLoop.

Bug: 296492988
Test: run simpleperf_unit_test
Change-Id: I2c66aa886aa99e671eafb41b28fc2c5fd700edf7
9 files changed