Bypass cancel error code during "Add another"

1. When user chooses "Add another" on latest fingerprint enroll page, we
   shall bypass RESULT_CANCELED from FingerprintEnrollEnrolling. This is
   because user has successfully enrolled a fingerprint before enter
   FingerprintEnrollFinish page.

2. In FingerprintEnrollFindSensor
   A. Do not call startLookingForFingerprint() if mNextClick is true
      because it is wating the result back from
      FingerprintEnrollEnrolling, and let onActivityResult() mehtod to
      handle correct behavior.
   B. Add tests for following cases
      a. Sidecar existence
      b. Activity recycled and recreate in order to get activity result.

Bug: 243701933
Bug: 243762418

Test: ROBOTEST for SetupFingerprintEnrollFindSensorTest,
   FingerprintEnrollFindSensorTest, SetupFingerprintEnrollFinishTest

Test: Test scenarios w/ and w/o always_finish_activities
  1. Enroll a fingerprint but cancel it during enrolling in SuW
  2. Enroll a fingerprint in SuW
  3. Add another fingerprint in SuW
  4. Run "Add another" but cancel it during enrolling in SuW
  5. W/o enrolled fingerprint, add first fingerprint in settings
  6. W/o enrolled fingerprint, add first fingerprint but cancel it
     during enrolling in settings
  7. W/o enrolled fingerprint, add first fingerprint and choose "Add
     another" in settings
  8. W/o enrolled fingerprint, add first fingerprint and choose "Add
     another" then cancel it during enrolling in settings
  9. W/ 1 enrolled fingerprint, add fingerprint in settings
  10. W/ 1 enrolled fingerprint, add fingerprint but cancel it during
      enrolling in settings
  11. W/ 1 enrolled fingerprint, add fingerprint and choose "Add
      another" in settings
  12. W/ 1 enrolled fingerprint, add fingerprint and choose "Add
      another" then canel it during enrolling in settings

Change-Id: I03d8d8ebc39eb34f8fc28acb5cd267e37c7a0311