BUILD.bazel: Explicitly set file modes
BUILD.bazel: Explicitly set file modes

Overriding the default 0555 [1,2], which doesn't make sense for
Terraform configs, etc.  Bazel still (as of 0.15.0) doesn't support
setting permissions for the tarball itself [3], but we can address
that in followup work if/when it becomes possible.

[1]: https://docs.bazel.build/versions/master/be/pkg.html#pkg_tar
[2]: https://github.com/bazelbuild/bazel/issues/2925
[3]: https://github.com/bazelbuild/bazel/issues/5588

derekhiggins/installer,derekhiggins/installer