Reopen Files for ClosedChannelException in BucketCache

When using the FileIOEngine for BucketCache, the cache will be disabled if the connection is interrupted or closed. HBase will then get ClosedChannelExceptions trying to access the file. After 60s, the RS will disable the cache. This causes severe read performance degradation for workloads that rely on this cache. FileIOEngine never tries to reopen the connection. This JIRA is to reopen files when the BucketCache encounters a ClosedChannelException.