PrebuildEtcModule no longer implements OutputFiles method

In the context of incremental soong, the output files
inter-module-communication will be through OutputFilesProvider.
The OutputFileProducer interface will be deprecated.

These module types are included in this change:
linker_config
llndk_libraries_txt
sanitizer_libraries_txt
java_sdk_library_xml
vndksp_libraries_txt
vndkcore_libraries_txt
vndkprivate_libraries_txt
vndkpublic_libraries_txt

Test: CI
Bug: 339477385
Change-Id: I35575bbad137df5ff8001db9a61ba5b3d13eaa6d
diff --git a/apex/apex.go b/apex/apex.go
index e79afad..4c97fdb 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -2128,7 +2128,7 @@
 			}
 		case prebuiltTag:
 			if prebuilt, ok := child.(prebuilt_etc.PrebuiltEtcModule); ok {
-				filesToCopy, _ := prebuilt.OutputFiles("")
+				filesToCopy := android.OutputFilesForModule(ctx, prebuilt, "")
 				for _, etcFile := range filesToCopy {
 					vctx.filesInfo = append(vctx.filesInfo, apexFileForPrebuiltEtc(ctx, prebuilt, etcFile))
 				}
@@ -2274,7 +2274,7 @@
 		// Because APK-in-APEX embeds jni_libs transitively, we don't need to track transitive deps
 	} else if java.IsXmlPermissionsFileDepTag(depTag) {
 		if prebuilt, ok := child.(prebuilt_etc.PrebuiltEtcModule); ok {
-			filesToCopy, _ := prebuilt.OutputFiles("")
+			filesToCopy := android.OutputFilesForModule(ctx, prebuilt, "")
 			for _, etcFile := range filesToCopy {
 				vctx.filesInfo = append(vctx.filesInfo, apexFileForPrebuiltEtc(ctx, prebuilt, etcFile))
 			}