Fixing flaky "TestExpireTime" test.
Fixing flaky "TestExpireTime" test.

It failed any time the clock ticked in between getting "now" and calling
Generate.

R=pthatcher@webrtc.org

Review URL: https://codereview.webrtc.org/1800833002 .

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#12000}

ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc