tests without requiring Abseil's tests be built (default=OFF)

This disables building libraries that are only used for writing tests
by default.

The logging library releases some libraries used for writing tests
that themselves depend on GoogleTest. This allows Abseil to build by
default without requiring GoogleTest.

Fixes #1262

PiperOrigin-RevId: 470847215
Change-Id: I296f41aa06d6f302853af3f32e1f762649504afc