Lower the index persistent logging to fine

Change-Id: I8b32d20569adcbe0b65a10e14bb7dcef3d89ee25

src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/CacheKeysIndex.java

diff --git a/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/CacheKeysIndex.java b/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/CacheKeysIndex.java
index 0730380..c402c87 100644
--- a/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/CacheKeysIndex.java
+++ b/src/main/java/com/googlesource/gerrit/modules/cache/chroniclemap/CacheKeysIndex.java
@@ -297,7 +297,7 @@
           metrics.persistFailures.increment();
           return;
         }
-        logger.atInfo().log("Cache keys index %s was persisted to %s file", name, indexFile);
+        logger.atFine().log("Cache keys index %s was persisted to %s file", name, indexFile);
       } catch (Exception e) {
         logger.atSevere().withCause(e).log("Persisting cache keys index %s failed", name);
         metrics.persistFailures.increment();