Implement the short-burst DTMF tones for CDMA calls.

- Add code to respect "burst" mode dtmf
  - includes adding code to read when radio has completed the dtmf tone
    and adding a queue of incoming dtmf presses while a dtmf tone is in
- Add a config overlay for mcc311/mnc480 to enable the setting in

Bug: 17431108
Change-Id: Icf1ec86ab54783e04b37104f6f3c327b959c4c0b
2 files changed