Add go_package to proto definition files (#17262)

* Add go_package to proto definition files

This fix tries to address the issue raised in 16282 by
add go_package to proto files, so that generated go files
have correct path.

This fix fixes 16282.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Add go_package to proto definition in tensorflow/core/framework

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Add go_package to proto definition in tensorflow/core/example

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Add go_package to proto definition in tensorflow/core/example

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>