Excessive allocations in Firebase Trace.incrementMetric

firebase-perf/src/main/java/com/google/firebase/perf/metrics/Trace.java

@@ -348,8 +348,16 @@ public void incrementMetric(@NonNull String metricName, long incrementBy) {
     // thread-safer
     Counter counter = obtainOrCreateCounterByName(metricName.trim());
     counter.increment(incrementBy);
-    logger.debug(
-        "Incrementing metric '%s' to %d on trace '%s'", metricName, counter.getCount(), name);
+    if (logger.isLogcatEnabled()) {
+      logger.debug(
+          "Incrementing metric '"
+              + metricName
+              + "' to "
+              + counter.getCount()
+              + " on trace '"
+              + name
+              + "'");
+    }
   }
 
   /**

firebase-perf/src/main/java/com/google/firebase/perf/metrics/validator/PerfMetricValidator.java

@@ -33,6 +33,8 @@ public abstract class PerfMetricValidator {
   private static final Pattern ATTRIBUTE_KEY_PATTERN =
       Pattern.compile("^(?!(firebase_|google_|ga_))[A-Za-z][A-Za-z_0-9]*");
 
+  private static final Constants.CounterNames[] validCounterNames = Constants.CounterNames.values();
+
   /**
    * Creates a list of PerfMetricValidator classes based on the contents of PerfMetric
    *
@@ -126,7 +128,6 @@ public static String validateMetricName(@Nullable String str) {
       return String.format(
           Locale.US, "Metric name must not exceed %d characters", Constants.MAX_COUNTER_ID_LENGTH);
     } else if (str.startsWith("_")) {
-      Constants.CounterNames[] validCounterNames = Constants.CounterNames.values();
       for (Constants.CounterNames counterName : validCounterNames) {
         if (counterName.toString().equals(str)) {
           return null;