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/test.go b/cc/test.go
index ae62128..7a6cf1b 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -700,7 +700,7 @@
 // TODO(b/244432609): handle `isolated` property.
 // TODO(b/244432134): handle custom runpaths for tests that assume runfile layouts not
 // default to bazel. (see linkerInit function)
-func testBinaryBp2build(ctx android.TopDownMutatorContext, m *Module) {
+func testBinaryBp2build(ctx android.Bp2buildMutatorContext, m *Module) {
 	var testBinaryAttrs testBinaryAttributes
 	testBinaryAttrs.binaryAttributes = binaryBp2buildAttrs(ctx, m)