Don't create a new module for bp2build conversion.

A performance improvement for bp2build as Blueprint/Soong no longer have
the overhead of additional modules. The creation of these modules
results in:
* traversal of additional modules for each subsequent mutator
* synchronization over a go channel to collect newly created modules:
https://cs.android.com/android/platform/superproject/+/master:build/blueprint/context.go;l=2594,2600;drc=1602226f23181b8c3fbfcaf3358f0297e839d7d3

We avoid both of these by storing the information directly in the
underlying module.

Also as a fringe benefit, removes some necessary boilerplate for
conversion.

For benchmarks, reduces runtime ~1% for 1% converted, ~24% for 100%
converted. See more: go/benchmarks-for-https:-r.android.com-1792714

Test: ran benchmarks/tests in bp2build
Test: build/bazel/ci/bp2build.sh
Change-Id: Ie9273b8cbab5bc6edac1728067ce184382feb211

cc/library_headers.go

@@ -111,18 +111,6 @@ type bazelCcLibraryHeadersAttributes struct {
 	System_dynamic_deps bazel.LabelListAttribute
 }
 
-type bazelCcLibraryHeaders struct {
-	android.BazelTargetModuleBase
-	bazelCcLibraryHeadersAttributes
-}
-
-func BazelCcLibraryHeadersFactory() android.Module {
-	module := &bazelCcLibraryHeaders{}
-	module.AddProperties(&module.bazelCcLibraryHeadersAttributes)
-	android.InitBazelTargetModule(module)
-	return module
-}
-
 func CcLibraryHeadersBp2Build(ctx android.TopDownMutatorContext) {
 	module, ok := ctx.Module().(*Module)
 	if !ok {
@@ -155,11 +143,5 @@ func CcLibraryHeadersBp2Build(ctx android.TopDownMutatorContext) {
 		Bzl_load_location: "//build/bazel/rules:cc_library_headers.bzl",
 	}
 
-	ctx.CreateBazelTargetModule(BazelCcLibraryHeadersFactory, module.Name(), props, attrs)
+	ctx.CreateBazelTargetModule(module.Name(), props, attrs)
 }
-
-func (m *bazelCcLibraryHeaders) Name() string {
-	return m.BaseModuleName()
-}
-
-func (m *bazelCcLibraryHeaders) GenerateAndroidBuildActions(ctx android.ModuleContext) {}