Description
When KMS server starts, it loads KeyProviderCryptoExtension and print the following message:
2017-08-17 04:57:13,348 INFO org.apache.hadoop.crypto.key.kms.server.KMSWebApp: Initialized KeyProviderCryptoExtension EagerKeyGeneratorKeyProviderCryptoExtension: KeyProviderCryptoExtension: CachingKeyProvider: jceks://file@/var/lib/kms/kms.keystore
However, this is confusing as KeyAuthorizationKeyProvider is loaded by not shown in this message. KeyAuthorizationKeyProvider#toString should be improved, so that in addition to its internal provider, also print its own class name when loaded.