KinesisRecordProcessor: Fix errorprone warning [FloggerLogString]

 [FloggerLogString] Arguments to log(String) must be compile-time
 constants or parameters annotated with @CompileTimeConstant.

 Use Flogger's formatting log methods instead.

Change-Id: Ia723b0213b1d6bd7e86e051bc7778f1a45235d59

src/main/java/com/googlesource/gerrit/plugins/kinesis/KinesisRecordProcessor.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/kinesis/KinesisRecordProcessor.java b/src/main/java/com/googlesource/gerrit/plugins/kinesis/KinesisRecordProcessor.java
index 598aa6c..b794aaf 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/kinesis/KinesisRecordProcessor.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/kinesis/KinesisRecordProcessor.java
@@ -122,7 +122,7 @@
   }
 
   private void checkpoint(RecordProcessorCheckpointer checkpointer) {
-    logger.atInfo().log("Checkpointing shard: " + kinesisShardId);
+    logger.atInfo().log("Checkpointing shard: %s", kinesisShardId);
     try {
       checkpointer.checkpoint();
     } catch (ShutdownException se) {