Floss: Add set_mps_qualification_enabled flag

Add a new flag `set_mps_qualification_enabled` for Bluetooth team to
enable qualification in the future.

After this change, when you use "btclient telephony enable" it will call
set_mps_qualification_enabled() instead of set_phone_ops_enabled().

Bug: 302485701
  pair Bluetooth Headset
  load https://google.git.io/libhidtelephoony/ with Chrome
  click on "Start", select the headset then "Connect"
  "Inputs Reports" and "Output Reports" are correct
  "Hook Switch", "Off-Hook" and "Ring" test cases are passed
  used https://online-voice-recorer.com during "Hook Switch" and
    "off-Hook" tests to check audio input
  Google Meet: headset is able to hang-up the call
Test: atest bluetooth_test_gd

Change-Id: I3c0dbafbd2f6b965a8366fa2b3f778fc0aba4ea0