alsa_sound: Remove pcm stream close for flushing buffers

- Currently pcm stream is closed to flush buffers while switching
  between speaker+headset combo device and headset device.
- Fix this problem by removing unnecessary pcm stream close.

Bug-id: 7051374
Change-Id: Id2faaeadd2a8e009f67e85beee42bbfe47b959f4
3 files changed
tree: 3688432e308620b93b5e641ba315d45e14845d5d
  1. alsa_sound/
  2. libalsa-intf/
  3. Android.mk