Minor optimization to avoid calling currentTimeMillis when not logging.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=187644617

Author: paulsowden

library/src/main/java/com/bumptech/glide/load/engine/Engine.java

@@ -166,7 +166,7 @@ public <R> LoadStatus load(
       boolean onlyRetrieveFromCache,
       ResourceCallback cb) {
     Util.assertMainThread();
-    long startTime = LogTime.getLogTime();
+    long startTime = VERBOSE_IS_LOGGABLE ? LogTime.getLogTime() : 0;
 
     EngineKey key = keyFactory.buildKey(model, signature, width, height, transformations,
         resourceClass, transcodeClass, options);