Track when last snapshot is created (#65768)

Encrypted snapshots are available on active PLATINUM and ENTERPRISE license modes.
Listing encrypted repositories, as well as restoring and deleting encrypted snapshots is still
permitted after the license expires or is downgraded, to avoid a data hostage situation.

This PR updates the last usage time stamp of the encrypted snapshots feature to the creation
time of the most recent encrypted snapshot.

Author: albertzaharovits

x-pack/plugin/repository-encrypted/src/main/java/org/elasticsearch/repositories/encrypted/EncryptedRepositoryPlugin.java

@@ -148,7 +148,7 @@ public Repository create(RepositoryMetadata metadata, Function<String, Repositor
                 if (false == (delegatedRepository instanceof BlobStoreRepository) || delegatedRepository instanceof EncryptedRepository) {
                     throw new IllegalArgumentException("Unsupported delegate repository type [" + DELEGATE_TYPE_SETTING.getKey() + "]");
                 }
-                if (false == getLicenseState().isAllowed(XPackLicenseState.Feature.ENCRYPTED_SNAPSHOT)) {
+                if (false == getLicenseState().checkFeature(XPackLicenseState.Feature.ENCRYPTED_SNAPSHOT)) {
                     logger.warn(
                         new ParameterizedMessage(
                             "Encrypted snapshots are not allowed for the currently installed license [{}]."