SettingsProvider: aconfig: do not error on missing flag files

    @GuardedBy("mLock")

    private void loadAconfigDefaultValuesLocked(List<String> filePaths) {

        for (String fileName : filePaths) {

            File f = new File(fileName);

            if (f.isFile() && f.canRead()) {

                try (FileInputStream inputStream = new FileInputStream(fileName)) {

                    loadAconfigDefaultValues(

                            inputStream.readAllBytes(), mNamespaceDefaults, mAconfigDefaultFlags);

                } catch (IOException e) {

                    Slog.e(LOG_TAG, "failed to read protobuf", e);

                }

            } else {

                Slog.d(LOG_TAG, "No protobuf file at " + fileName);

            }

        }

    }