Add "NO CHECKED-IN PROTOBUF GENCODE" to Protobuf Java gencode.

PiperOrigin-RevId: 616131629

src/google/protobuf/compiler/java/file.cc

@@ -243,6 +243,9 @@ void FileGenerator::Generate(io::Printer* printer) {
   // fully-qualified names in the generated source.
   printer->Print(
       "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
+      "// NO CHECKED-IN PROTOBUF "
+      // Intentional line breaker
+      "GENCODE\n"
       "// source: $filename$\n",
       "filename", file_->name());
   if (options_.opensource_runtime) {
@@ -520,6 +523,9 @@ static void GenerateSibling(
 
   printer.Print(
       "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
+      "// NO CHECKED-IN PROTOBUF "
+      // Intentional line breaker
+      "GENCODE\n"
       "// source: $filename$\n",
       "filename", descriptor->file()->name());
   if (opensource_runtime) {
@@ -600,6 +606,9 @@ std::string FileGenerator::GetKotlinClassname() {
 void FileGenerator::GenerateKotlin(io::Printer* printer) {
   printer->Print(
       "// Generated by the protocol buffer compiler. DO NOT EDIT!\n"
+      "// NO CHECKED-IN PROTOBUF "
+      // Intentional line breaker
+      "GENCODE\n"
       "// source: $filename$\n"
       "\n",
       "filename", file_->name());
@@ -638,6 +647,9 @@ void FileGenerator::GenerateKotlinSiblings(
 
     printer.Print(
         "// Generated by the protocol buffer compiler. DO NOT EDIT!\n"
+        "// NO CHECKED-IN PROTOBUF "
+        // Intentional line breaker
+        "GENCODE\n"
         "// source: $filename$\n"
         "\n",
         "filename", descriptor->file()->name());

src/google/protobuf/compiler/java/shared_code_generator.cc

@@ -59,6 +59,9 @@ void SharedCodeGenerator::Generate(
     std::string info_full_path = absl::StrCat(filename, ".pb.meta");
     printer->Print(
         "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
+        "// NO CHECKED-IN PROTOBUF "
+        // Intentional line breaker
+        "GENCODE\n"
         "// source: $filename$\n",
         "filename", file_->name());
     if (options_.opensource_runtime) {