title: How to use Biometric Prompt API in versions lower than Android 9.0
body: <p>I am trying to implement Biometric prompt API to authenticate user using fingerprint verification. I am successfully able to integrate Biometric prompt and it is working on andorid 9.0. But as the documentation suggests Biometric api is also backwards compatible, but when I build dialog using below code it shows API support warning. </p>
  
  <blockquote>
    <p>Call requires API level 28 (current min is 15): new
    android.hardware.biometrics.BiometricPrompt.Builder less... (Ctrl+F1) 
    This check scans through all the Android API calls in the application
    and warns about any calls that are not available on all versions
    targeted by this application (according to its minimum SDK attribute
    in the manifest)</p>
  </blockquote>
  
  <pre><code>mBiometricPrompt = new BiometricPrompt.Builder(this)
                          .setDescription("Description")
                          .setTitle("Title")
                          .setSubtitle("Subtitle")
                          .setNegativeButton("Cancel", getMainExecutor(), new DialogInterface.OnClickListener() {
                              @Override
                              public void onClick(DialogInterface dialogInterface, int i) {
                                  Log.i(TAG, "Cancel button clicked");
                              }
                          })
                          .build();
  </code></pre>
  
  <p>What can I do to make this work on lower apis? Here is Screenshot.
  <a href="https://i.stack.imgur.com/dalHz.png" rel="noreferrer"><img src="https://i.stack.imgur.com/dalHz.png" alt="enter image description here"></a></p>