Hearing Aid Dump Audio Tool: Add dump debug buffer feature

Add dump HearingAid debug buffer feature to let the HearingAid debug
information dump to debug file and make it readable.

Bug: 130781854
Test: ./dump_hearingaid_audio.py -d true btsnoop_hci.log
      ./dump_hearingaid_audio.py -sd true btsnoop_hci.log

Change-Id: I150fd897e6f197d5b853554734926ad613de4e6b