Added null check to fingerprint fragment

Test: It builds.
Fixes: 167619037
Change-Id: I76fdfd9f4be412b5f47fb05a772f7973fe6676da

src/com/android/settings/biometrics/fingerprint/FingerprintSettings.java

@@ -670,7 +670,9 @@ public class FingerprintSettings extends SubSettings {
             mRemovalSidecar.startRemove(fingerPrint, mUserId);
             String name = genKey(fingerPrint.getBiometricId());
             Preference prefToRemove = findPreference(name);
+            if (prefToRemove != null) {
                 prefToRemove.setEnabled(false);
+            }
             updateAddPreference();
         }