Fix odd values in aaudio metrics.

1. Do not log the AudioStream information if it is from the service. The
service side may automatically create an AudioStreamInternal instance
when a shared endpoint is used. This is not the interesting part for the
metrics.

2. If the aaudio stream uses legacy path, only channel mask will be
logged. Calculate channel count from channel mask for logging aaudio
metrics.

Test: atest AAudioTests MediaMetricsAtomTests
Test: dumpsys media.metrics
Bug: 194937266
Change-Id: I183224a4acc59c40d511ee2eb37da05210851348