CTA2075: Fix possible race condition

When accessing the MediaCodecs from the audio service callback the
client can still change the codecs which are tracked for receiving
updates. Hence, lock the parameterupdate when iterating over the
loudness controller codecs.

Test: atest "CtsMediaAudioTestCases:android.media.audio.cts.LoudnessCodecControllerTest#multipleLcc_withRegisteredCodecs_triggerUpdate" --iterations 100
Bug: 321868864
Change-Id: I7aedc85d9d143497d089ae7f613f9fb5897f916d