chore(deps): Bump tensorflow in /cmd/suggestion/nasrl/v1alpha3

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 1.14.0 to 1.15.2.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v1.14.0...v1.15.2)

Signed-off-by: dependabot[bot] <support@github.com>

cmd/suggestion/nasrl/v1alpha3/requirements.txt

@@ -1,4 +1,4 @@
 grpcio==1.23.0
 protobuf==3.9.1
 googleapis-common-protos==1.6.0
-tensorflow==1.14.0
+tensorflow==1.15.2