BlobStore may not be respecting size limit in findEntriesSince()

The heap dump of an OOM storage node revealed a log message from AmbryRequests.handleReplicaMetadataRequest() that was over 1GB.
The log line in question is:
publicAccessLogger.info("{} {} processingTime {}", replicaMetadataRequest, response, processingTime);
And the ReplicaMetadataResponse object apparently has a huge list.

We will add some logging/metrics to track when this happens and debug it.

java.lang.OutOfMemoryError: Java heap space
    at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:133)
    at java.io.OutputStreamWriter.write(OutputStreamWriter.java:220)
    at java.io.Writer.write(Writer.java:157)
    at org.apache.log4j.helpers.QuietWriter.write(QuietWriter.java:48)
    at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
    at org.apache.log4j.DailyRollingFileAppender.subAppend(DailyRollingFileAppender.java:369)
    at org.apache.log4j.WriterAppender.append(WriterAppender.java:162)
    at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
    at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)
    at org.apache.log4j.Category.callAppenders(Category.java:206)
    at org.apache.log4j.Category.forcedLog(Category.java:391)
    at org.apache.log4j.Category.log(Category.java:856)
    at org.slf4j.impl.Log4jLoggerAdapter.info(Log4jLoggerAdapter.java:363)
    at com.github.ambry.server.AmbryRequests.handleReplicaMetadataRequest(AmbryRequests.java:647)
    at com.github.ambry.server.AmbryRequests.handleRequests(AmbryRequests.java:169)
    at com.github.ambry.server.RequestHandler.run(RequestHandler.java:46)
    at java.lang.Thread.run(Thread.java:745)```

Start by tracing BlobStore.findEntriesSince() and AmbryRequests.handleReplicaMetadataRequest(), focusing on how the ReplicaMetadataResponse list can become unexpectedly large. Use the reported logging path and OOM trace to determine what observability is needed and what evidence would show that the size limit is being respected.