Flip default for --incompatible_default_to_explicit_init_py

[alexeagle]

Help to finish bazelbuild/bazel#10076 by setting the flag value explicitly in existing Bazel CI projects, then land a PR in Bazel to change the default value.

[hofbi]

@cgrindel I could land bazelbuild/bazel#27674. Could you assign this ticket to me and close it?

[cgrindel]

@hofbi asked me to close this ticket.

[hofbi]

@cgrindel so sorry, I linked the wrong ticket. #41 (comment) is the correct one. Could you undo the changes to this ticket (unassign and reopen). Sorry again.