bp2build: add converted modules to codegen metrics, and remove the
compat layer.

The list of converted modules is used for tracking bp2build progress.

The module_name_to_label aliases weren't really adding much value to
mixed builds, so let's drop the feature for now and simplify the code.

Test: CI
Test: USE_BAZEL_ANALYSIS=1 m droid
Change-Id: I3269344cfe6d1c72c108d66c6e820bc0ec19bb34
diff --git a/bp2build/bp2build.go b/bp2build/bp2build.go
index 48b2945..45a3cb6 100644
--- a/bp2build/bp2build.go
+++ b/bp2build/bp2build.go
@@ -43,7 +43,7 @@
 	writeFiles(ctx, bp2buildDir, bp2buildFiles)
 
 	soongInjectionDir := android.PathForOutput(ctx, bazel.SoongInjectionDirName)
-	writeFiles(ctx, soongInjectionDir, CreateSoongInjectionFiles(res.compatLayer))
+	writeFiles(ctx, soongInjectionDir, CreateSoongInjectionFiles(res.metrics))
 
 	return res.metrics
 }