Merge changes I35aae129,I59239c39,Id685bf74,Ic4f27fdb,I2a2b6b50 am: 2a74fe2f63
am: da2d3e03be

* commit 'da2d3e03be9f3ee0b40ab90083023d6bfdc3f87b':
  Add a gdb_flags argument to gdbrunner.start_gdb.
  Allow gdbrunner.start_gdbserver to not upload gdbserver.
  Add get_pids helper to gdbrunner.
  Don't throw when we fail to find a device.
  Allow selection of adb command.