Revert "Wait for thread termination in PreZygoteFork()"

Revert submission 2782117-daemon_wait

Reason for revert: Caused 689-zygote-jit-deopt failure, probably others

Reverted changes: /q/submissionid:2782117-daemon_wait

Bug: 299221079
Bug: 304183774
Change-Id: Idc5d0ba07c5de1f2c6c1bbc7bfabebeee65951a1
3 files changed