Clean up misc Javadoc and deprecation warnings

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=136156922

java/google/registry/monitoring/metrics/MetricMetrics.java

@@ -49,6 +49,7 @@ final class MetricMetrics {
               LABELS);
 
   /** A gauge representing a snapshot of the number of active timeseries being reported. */
+  @SuppressWarnings("unused")
   private static final Metric<Long> timeseriesCount =
       MetricRegistryImpl.getDefault()
           .newGauge(

java/google/registry/rde/RdeImportUtils.java

@@ -135,8 +135,7 @@ public class RdeImportUtils {
     // TODO (wolfgang): Add validation method for IDN tables
     try (InputStream input =
         gcsUtils.openInputStream(new GcsFilename(escrowBucketName, escrowFilePath))) {
-      try {
-        RdeParser parser = new RdeParser(input);
+      try (RdeParser parser = new RdeParser(input)) {
         // validate that tld exists and is in PREDELEGATION state
         String tld = parser.getHeader().getTld();
         try {