Update version numbers to 2.20.0

Author: tensorflow-jenkins

.bazelrc

@@ -77,7 +77,7 @@
 # third_party/tensorflow/tools/pip_package/setup.oss.py.tpl
 build --repo_env=ML_WHEEL_TYPE="snapshot"
 build --repo_env=ML_WHEEL_BUILD_DATE=""
-build --repo_env=ML_WHEEL_VERSION_SUFFIX="-rc0"
+build --repo_env=ML_WHEEL_VERSION_SUFFIX=""
 
 # For projects which use TensorFlow as part of a Bazel build process, putting
 # nothing in a bazelrc will default to a monolithic build. The following line