audio policy: disable A2DP suspend when flag use_bt_sco_for_media is enabled

The internal A2DP suspend mechanism is not needed anymore with the new
implementation in java audioservice.
With the introduction of more complex A2DP routing patterns with the
spatializer mixer, offload and software encoder path, it has become
prone to leakage of the suspended state.
At first disable it only when use_bt_sco_for_media flag is enabled
before completely removing it.

Bug: 407477045
Test: repor steps in bug
Flag: com.android.media.audioserver.use_bt_sco_for_media
Change-Id: I9f6206d185860382fb55d23881a04734f37c0250