bp2build: remove manifest file for bp2build-sync.

The latter doesn't exist anymore, so there's no more need for the
bp2build file manifest.

Bug: 185817076
Test: TH
Change-Id: I6638b84eb371ced98474e3ca5026e3b33b824767
diff --git a/bp2build/bp2build.go b/bp2build/bp2build.go
index f1bf648..cf6994f 100644
--- a/bp2build/bp2build.go
+++ b/bp2build/bp2build.go
@@ -18,7 +18,6 @@
 	"android/soong/android"
 	"fmt"
 	"os"
-	"strings"
 )
 
 // Codegen is the backend of bp2build. The code generator is responsible for
@@ -36,18 +35,12 @@
 	for _, f := range filesToWrite {
 		p := getOrCreateOutputDir(outputDir, ctx, f.Dir).Join(ctx, f.Basename)
 		if err := writeFile(ctx, p, f.Contents); err != nil {
-			fmt.Errorf("Failed to write %q (dir %q) due to %q", f.Basename, f.Dir, err)
+			panic(fmt.Errorf("Failed to write %q (dir %q) due to %q", f.Basename, f.Dir, err))
 		}
 		// if these generated files are modified, regenerate on next run.
 		generatedBuildFiles = append(generatedBuildFiles, p.String())
 	}
 
-	// The MANIFEST file contains the full list of files generated by bp2build, excluding itself.
-	// Its purpose is for downstream tools to understand the set of files converted by bp2build.
-	manifestFile := outputDir.Join(ctx, "MANIFEST")
-	writeFile(ctx, manifestFile, strings.Join(generatedBuildFiles, "\n"))
-	generatedBuildFiles = append(generatedBuildFiles, manifestFile.String())
-
 	return metrics
 }