Reverb: Fix bug causing same item tests to sometimes deadlock.
Reverb: Fix bug causing same item tests to sometimes deadlock.

PiperOrigin-RevId: 308821553
Change-Id: I3f321e484b426f2fb8a7e26ec10627c8a42775e5

deepmind/reverb,deepmind/reverb,deepmind/reverb,deepmind/reverb