LeAudio: Calculate proper strategy for mic-only LE Audio devices

Use remote source PAC records when the remote is a source-only device.
Currently we calculate the strategy only for the remote sink direction.

Bug: 388499616
Test: atest bluetooth_le_audio_test
Flag: Exempt: day to day fix
Change-Id: Iea4a6d8b13edadf7a9bbd29cd25a7aceee9ad0d4