Revert "Refactor of screenshot code on main thread."

This reverts commit b43b58378679bf4ac8d0837047187d4509bc45d8.

Reason for revert: Appstartup regression found in b/327488235

Change-Id: I8d975b81afd2cde1d543e8bc7e730a6e42393bec
3 files changed