Merge changes I48e01da5,Ic6a7bff6,I9a568d60,Id1b5926a

* changes:
  Add stack/acl/btm_acl::link_policy_text
  Add stack/include/gatt_api::gatt_op_code_text
  Add API tL2C_LCB::number_of_active_dynamic_channels
  Add stack/l2cap/l2c_api::fixed_channel_text