Add bootloader to IMAGES/ subdir of soong built target_files.zip

This matches the make behavior.

Test: Built the target_files.zip locally
Bug: 388635097
Change-Id: Iac789a4c666682149e3ab78938695d7a521d4db5
diff --git a/filesystem/android_device.go b/filesystem/android_device.go
index 555eddc..6a939e8 100644
--- a/filesystem/android_device.go
+++ b/filesystem/android_device.go
@@ -210,6 +210,9 @@
 
 	// Create an IMAGES/ subdirectory
 	builder.Command().Textf("mkdir -p %s/IMAGES/", targetFilesDir.String())
+	if a.deviceProps.Bootloader != nil {
+		builder.Command().Textf("cp ").Input(android.PathForModuleSrc(ctx, proptools.String(a.deviceProps.Bootloader))).Textf(" %s/IMAGES/bootloader", targetFilesDir.String())
+	}
 
 	for _, zipCopy := range toCopy {
 		if zipCopy.srcModule == nil {