Dump the required modules into module-info.json

Certain applications, like tracking the dependency chain of modules,
knowing the "required" dependencies is required.

In this context, "required" here means the `required` field in
Android.bp files.

Bug: 339193439
Test: Inspect module-info.json for the `required` field
Change-Id: I420c781d410e715ef86823278f99e4ffe51f8022