leaudio: Fix crash when data path is removed while ACL is disconnected

Fixes race condition.

Bug: 253034131
Test: atest BluetoothInstrumentationTests
Test: manual - initiate disconnection of one earbud
Tag: #feature
Merged-In: I49709207790104ffa03e419205e7bda9c7802241
Change-Id: I49709207790104ffa03e419205e7bda9c7802241
(cherry picked from commit 69fbad85)