Fix flaky fingerprintUdfpsOverlayEnrollment_PlaysAllAnimationsAssetsCorrectly

We should return the corresponding getStageThresholdSteps() for udfps test,
otherwise the test can simulate last stage only and make the test fail.

Bug: 228100413
Bug: 260659253
Test: make RunSettingsRoboTests ROBOTEST_FILTER= \
"com.android.settings.biometrics.fingerprint .FingerprintEnrollEnrollingTest"

Change-Id: I4c712c84f357f275e5a169d16d2ed382fa4494ef