add support for legacy (pre-4.3) platform

It seems systrace-legacy.py had not maintained for a while and has some
bugs and missing features.
So implement atrace_legacy_agent to use legacy platforms.

Change-Id: I9a60c4d9899cff5d088d00c8be643493fc163272
Signed-off-by: Young-Ho Cha <ganadist@gmail.com>
3 files changed