Merge changes Ic28ba99f,I353efe8c,I2c0908fd,I860b744c,Icc9ad82c

* changes:
  Remove bta knowledge of hci handle
  Streamline bta/dm/::bta_dm_acl_up/down
  Add API stack/acl/btm_acl::acl_peer_supports_sniff_subrating
  Remove def bta/dm/BTM_SSR_INCLUDED
  Rework api ret val BTA_DmGetConnectionState