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/cc/binary.go b/cc/binary.go
index 4606b62..0722f81 100644
--- a/cc/binary.go
+++ b/cc/binary.go
@@ -599,7 +599,7 @@
 	handler.module.setAndroidMkVariablesFromCquery(info.CcAndroidMkInfo)
 }
 
-func binaryBp2buildAttrs(ctx android.TopDownMutatorContext, m *Module) binaryAttributes {
+func binaryBp2buildAttrs(ctx android.Bp2buildMutatorContext, m *Module) binaryAttributes {
 	baseAttrs := bp2BuildParseBaseProps(ctx, m)
 	binaryLinkerAttrs := bp2buildBinaryLinkerProps(ctx, m)
 
@@ -661,7 +661,7 @@
 	return attrs
 }
 
-func binaryBp2build(ctx android.TopDownMutatorContext, m *Module) {
+func binaryBp2build(ctx android.Bp2buildMutatorContext, m *Module) {
 	// shared with cc_test
 	binaryAttrs := binaryBp2buildAttrs(ctx, m)