leaudio: Fix speedup reconfig

Make sure that there is a valid context type when reconfiguring after
phone call.
With this we avoid reconfiguration for unspecified context.

Bug: 331775328
Bug: 352686917
Flag: com.android.bluetooth.flags.leaudio_speed_up_reconfiguration_between_call
Test: atest bluetooth_le_audio_client_test
Change-Id: Iebc184207dc48618c27910aa1866ddc41b4c48c0