Fix restore position warning and static track adjustment

Remove unnecessary restoreTrack_l() position warning when
AudioTrack output device changes.

Also, fix rare getPosition() offset error if a static track is
continuously playing a long time (> 24 hours at 48khz sampling)
and its output device changes.

Bug: 22524122
Bug: 21699132
Change-Id: I5a35c13d62ff9f0702b09d5cd9362c730364b18c