leaudio: Decrease state machine transition timeout.

3.5 sec shall be far enought for the stream setup.
Previous value 5 sec was longer which is Audio HAL using (4.5) and that
could cause issues.

Bug: 216466543
Bug: 150670922
Test: atest --host bluetooth_le_audio_test
bluetooth_le_audio_client_test
Sponsor: @jpawlowski

Change-Id: I8d21876700c7048e3bdabb9c47a1e7911ab9cf68