dashboard/app: fix fix bisection tests
dashboard/app: fix fix bisection tests

Currently TestBisectFixRetry  fails because it assumes emails
about crash on ToT are not sent. But we currently send them
in tests. Make the behavior consistent between tests and prod.

Update #1371

google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller