bazel: replace bazel_tools//platforms use
bazel: replace bazel_tools//platforms use

This is going away in newer bazel versions

Signed-off-by: Keith Smiley <cadcacca0656fa2178c91a0e61e28374cd3a79c3@gmail.com>

envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy