simpleperf: prepare for adding user api.

In record cmd, add --stdio-controls-profiling option to
pause/resume profiling. It reads cmds from stdin,
and writes replies to stdout.
Add --log-to-android-buffer option to show simpleperf
logs in logcat.

Bug: 123717243
Test: run simpleperf through user api manually.
Test: run simpleperf_unit_test.

Change-Id: I6c32c669d003cbd670a45e6fd31f764656837111
8 files changed