@Override
  public void removeCredential(String clusterName, String alias, CredentialStoreType credentialStoreType) throws AmbariException {
    if (isInitialized(credentialStoreType)) {
      getCredentialStore(credentialStoreType).removeCredential(canonicalizeAlias(clusterName, alias));
    }
  }
Adds a new credential to either the persistent or the temporary CredentialStore
<p/>
The supplied key will be converted into UTF-8 bytes before being stored.
<p/>
The alias name will be canonicalized as follows:
<ul>
<li>if a cluster name is supplied, then "cluster.name." will be prepended to it</li>
<li>the characters will converted to all lowercase</li>
</ul>
Only a single instance of the named credential will be stored, therefore if a credential with
alias ALIAS1 is stored in the persisted CredentialStore and a call is made to store a credentials
with alias ALIAS1 into the temporary CredentialStore, the instance in the persisted CredentialStore
will be removed.

@param clusterName         the name of the cluster this credential is related to
@param alias               a string declaring the alias (or name) of the credential
@param credential          the credential value to store
@param credentialStoreType a CredentialStoreType indicating which credential store facility to use
@throws AmbariException
ambari-server/src/main/java/org/apache/ambari/server/security/encryption/CredentialStoreServiceImpl.java