Implements DQNReg as discovered in "Evolving RL Algorithms" https://arxiv.org/abs/2101.03958
Implements DQNReg as discovered in "Evolving RL Algorithms" https://arxiv.org/abs/2101.03958

PiperOrigin-RevId: 377311179
Change-Id: I47e6f841d9a4d2f79956c711b09cc008d862c511

deepmind/acme,deepmind/acme