Revert "Remove A2DP Source/Sink startup calls during A2DP initialization"

This reverts commit 801d56dc.

Reason for revert:
Prevents audio routing due to stale active device record if
Bluetooth is toggled without the process stopping completely
(ex. LE-only mode).

Bug: 72701090
Change-Id: Ifa798e63df14855b5bf0bd45e1557315cd51034d
Fixes: 73601288