hal: test: Fix crash issue during multistream playback

- At EOS crash is seen during multi stream(Main and Assoc) playback.
  This happens if Main stream ends before Assoc stream.
  Here Main stream thread force closes Associated stream in
  Main stream thread context while Associated thread is still
  accessing resorces.

-Fix this by avoiding force close of assoc stream in main thread context.

CRs-Fixed: 2061208
Change-Id: Ib6e6ce763187eef48ae54a1e33ce898712a2c289