title: Unresolved reference: MasterKey
body: <p>I am trying to follow examples given here:
  <a href="https://developer.android.com/topic/security/data" rel="nofollow noreferrer">https://developer.android.com/topic/security/data</a></p>
  <p>I have included the required libraries in my gradle:</p>
  <pre><code>implementation &quot;androidx.security:security-crypto:1.0.0&quot;
  
  // For Identity Credential APIs
  implementation &quot;androidx.security:security-identity-credential:1.0.0-alpha02&quot;
  </code></pre>
  <p>And yet when I try to use the code:</p>
  <pre><code>val mainKey = MasterKey.Builder(applicationContext)
      .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
      .build()
  </code></pre>
  <p>I get unresolved reference: MasterKey error. Does the library have that class at all?</p>
  <p>Thanks in advance.</p>