SurfaceFlinger: fix wake up time when sf duration change

When SF changes its work duration, it may already have a scheduled
wake up callback. In this case the callback needs to be updated with the
new duration.

Bug: 172683933
Test: launch an app and observe systraces
Change-Id: Ie63cd5fa3f82f193cfba031bbbc0b4f8bf8086a9
3 files changed