Remove dependency on libbacktrace.

libbacktrace is being deprecated, so move the maps reading code
to use libprocinfo since that is meant to be the android maps
reading code.

Bug: 120606663

Test: Ran on device.
Test: All unit tests pass.
Change-Id: Ie695706d7b9806224942a056c82d9e70503b4dac
2 files changed