am b9184809: Merge changes from topic \'gdbclient.py\'

* commit 'b9184809e7e3305d49a7a5a1c237538d9efec15a':
  Add gdbrunner package for shared functionality.
  Add get_props to adb.py's AndroidDevice.
  Add remount to adb.py's AndroidDevice.
  Add shell_popen method to adb.py.
  Add helper functions for `adb -e/-d` to adb.py.