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/bp2build/testing.go b/bp2build/testing.go
index dbabc06..b30f8ee 100644
--- a/bp2build/testing.go
+++ b/bp2build/testing.go
@@ -497,7 +497,7 @@
 	return m.props.Dir
 }
 
-func (m *customModule) ConvertWithBp2build(ctx android.TopDownMutatorContext) {
+func (m *customModule) ConvertWithBp2build(ctx android.Bp2buildMutatorContext) {
 	if p := m.props.One_to_many_prop; p != nil && *p {
 		customBp2buildOneToMany(ctx, m)
 		return
@@ -552,7 +552,7 @@
 
 }
 
-func (m *customModule) createConfigSetting(ctx android.TopDownMutatorContext) {
+func (m *customModule) createConfigSetting(ctx android.Bp2buildMutatorContext) {
 	csa := bazel.ConfigSettingAttributes{
 		Flag_values: bazel.StringMapAttribute{
 			"//build/bazel/rules/my_string_setting": m.Name(),
@@ -587,7 +587,7 @@
 
 // A bp2build mutator that uses load statements and creates a 1:M mapping from
 // module to target.
-func customBp2buildOneToMany(ctx android.TopDownMutatorContext, m *customModule) {
+func customBp2buildOneToMany(ctx android.Bp2buildMutatorContext, m *customModule) {
 
 	baseName := m.Name()
 	attrs := &customBazelModuleAttributes{}