Always merge build files

Previous behavior:

- Packge not listed in bp2buildKeepExistingBuildFile:
    - Use bp2build generated build file
- Package listed in bp2buildKeepExistingBuildFile:
    - Use handcrafted build file even if there were allowlisted bp2build
      modules in the same package.
- Package listed in bp2buildKeepExistingBuildFile and a soong module has
  a bp2build: { label } attribute:
    - Merge the handcrafted and bp2build generated build files

New behavior:

- Packge not listed in bp2buildKeepExistingBuildFile:
    - Use bp2build generated build file
- Package listed in bp2buildKeepExistingBuildFile:
    - Merge with bp2build generated build file.

Bug: 234167862
Test: ./build/bazel/ci/bp2build.sh
Change-Id: Ifbaf4f8f0f5158b5b2bd6d534eb2311e2e5f399b
diff --git a/bp2build/conversion.go b/bp2build/conversion.go
index 8cf9bea..d98b6a3 100644
--- a/bp2build/conversion.go
+++ b/bp2build/conversion.go
@@ -2,7 +2,6 @@
 
 import (
 	"encoding/json"
-	"fmt"
 	"reflect"
 	"strings"
 
@@ -80,21 +79,14 @@
 		files = append(files, newFile(bazelRulesSubDir, "soong_module.bzl", generateSoongModuleBzl(ruleShims)))
 	}
 
-	files = append(files, createBuildFiles(cfg, buildToTargets, mode)...)
+	files = append(files, createBuildFiles(buildToTargets, mode)...)
 
 	return files
 }
 
-func createBuildFiles(cfg android.Config, buildToTargets map[string]BazelTargets, mode CodegenMode) []BazelFile {
+func createBuildFiles(buildToTargets map[string]BazelTargets, mode CodegenMode) []BazelFile {
 	files := make([]BazelFile, 0, len(buildToTargets))
-	warnNotWriting := cfg.IsEnvTrue("BP2BUILD_VERBOSE")
 	for _, dir := range android.SortedStringKeys(buildToTargets) {
-		if mode == Bp2Build && android.ShouldKeepExistingBuildFileForDir(dir) {
-			if warnNotWriting {
-				fmt.Printf("[bp2build] Not writing generated BUILD file for dir: '%s'\n", dir)
-			}
-			continue
-		}
 		targets := buildToTargets[dir]
 		targets.sort()