Change saved_model_test back to use assertAllClose.
Change saved_model_test back to use assertAllClose.

We are dealing here with floating point values, so some small errors can
happen.

PiperOrigin-RevId: 322948216
Change-Id: I4dc8e7f728f6e3500bbf5546bbba2b418d14b13f

deepmind/sonnet,deepmind/sonnet