SurfacePackageFlickerTest: Fix an unlikely possible source of flakyness

To be flake-free, we need to wait on the first draw before we start
recording. However this is unlikely to happen in practice since
we already have a long delay.

Bug: 222749939
Test: SurfacePackageFlickerTest
Change-Id: I87743b6f964553426ffd056cf80babb38bfa55be
3 files changed