Have ConvertWBp2build use Bp2buildMutatorContext

This no-op refactoring facilitates some upcoming functional changes for
"bp2build allowlist v2". The work requires that the bp2build conversion
mutator be changed from a TopDown mutator to a BottomUp mutator.
Refactoring all bp2build-related methods so that they use Bp2buildMutatorContext
makes it easier to make this functional change without touching tens of
files and multiple projects.

Bug: 285631638
Test: m bp2build
Change-Id: I3d1ef3064146e959c6f0dc315350fc9764bf2bd2
diff --git a/etc/prebuilt_etc.go b/etc/prebuilt_etc.go
index c48bafa..9314e0c 100644
--- a/etc/prebuilt_etc.go
+++ b/etc/prebuilt_etc.go
@@ -712,7 +712,7 @@
 // Bp2buildHelper returns a bazelPrebuiltFileAttributes used for the conversion
 // of prebuilt_*  modules. bazelPrebuiltFileAttributes has the common attributes
 // used by both prebuilt_etc_xml and other prebuilt_* moodules
-func (module *PrebuiltEtc) Bp2buildHelper(ctx android.TopDownMutatorContext) (*bazelPrebuiltFileAttributes, bool) {
+func (module *PrebuiltEtc) Bp2buildHelper(ctx android.Bp2buildMutatorContext) (*bazelPrebuiltFileAttributes, bool) {
 	var src bazel.LabelAttribute
 	for axis, configToProps := range module.GetArchVariantProperties(ctx, &prebuiltEtcProperties{}) {
 		for config, p := range configToProps {
@@ -791,7 +791,7 @@
 // ConvertWithBp2build performs bp2build conversion of PrebuiltEtc
 // prebuilt_* modules (except prebuilt_etc_xml) are PrebuiltEtc,
 // which we treat as *PrebuiltFile*
-func (module *PrebuiltEtc) ConvertWithBp2build(ctx android.TopDownMutatorContext) {
+func (module *PrebuiltEtc) ConvertWithBp2build(ctx android.Bp2buildMutatorContext) {
 	var dir = module.installDirBase
 	// prebuilt_file supports only `etc` or `usr/share`
 	if !(dir == "etc" || dir == "usr/share") {