Bp2Build common properties auto-handling

Introduce `commonAttributes` & `fillCommonBp2BuildModuleAttrs used in
CreateBazelTargetModule

Adapt `bp2BuildInfo` to use `commonAttrs` instead of `Name`.
And thus also all downstream users of `CreateBazelTargetModule`.

As initial user, the Soong `required` property will be
translated to Bazel's `data`.

Bug: 198146582, 196091467
Test: build_converstion_test.go:TestCommonBp2BuildModuleAttrs
Test: go test
Test: mixed_{libc,droid}.sh
Change-Id: Ib500e40f7e2cb48c459f1ebe3188962fc41ec124