Hearing Aid: Add python script to dump audio data to file

Bug: 121005659
Test: ./dump_hearingaid_audio.py btsnoop_hci.log
      ./dump_hearingaid_audio.py -f folder btsnoop_hci.log
      ./dump_hearingaid_audio.py -f folder -c1 1 -c2 3 btsnoop_hci.log
      ./dump_hearingaid_audio.py -f folder -a 121 btsnoop_hci.log
Change-Id: I304531ecb5c5bd6cfc264130176d26acc60a64c2