Fix ATRACE_TAG redefinition in SysTrace.h

Split SysTrace.h into SysTrace.cpp to avoid defining ATRACE_TAG
in the clients of SysTrace.h

This is in preparation to land aosp/2190022

Test: m
Bug: 161393989
Change-Id: I0ed94c9f66043aa83a59e8042ec9e61ee47db0f2
2 files changed