Remove stale copy of ext/trace_config.h
Remove stale copy of ext/trace_config.h

The old file was left checked in ending up with a dupe vs the one
in include/perfetto/core/trace_config.h

Change-Id: Iafe5f6fbe14a515914e3c7541f0efaa2f4cbe1dd
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto