Skip entering PIP when dismissing auto-enter pip task

- Revert some changes from ag/14827090, we don't actually need to
  screenshot when dismissing, but we do need to prevent pip

Bug: 190751761
Test: Swiping up from YT -> PIP
      Swiping up from YT to Overview to home -> PIP
      Swiping up from YT to Overview
Change-Id: I2057467d5146be6edc382d3745a1e5269cd76a6b