Merge "libbacktrace: only build libbacktrace_offline static library." am: f20e4b1
am: b150324

* commit 'b1503248f4baa28ed739948a51da370bf40037ea':
  libbacktrace: only build libbacktrace_offline static library.

Change-Id: I903f82a38022f7094b70bc8e4d59ac5098456571