Update confirm device credentials to spec, add fingerprint

- New strings in the screen.
- New layout/style.
- Clean up internal API's around it.
- Add fingerprint support if launched from externally
- Separate theme if launched from externally
- If launched from above Keyguard, use SHOW_WHEN_LOCKED flag

Change-Id: Icdf9bf9e0506841f24e8aab5f0f1d1f4b688951f

src/com/android/settings/CredentialStorage.java

@@ -439,9 +439,8 @@ public final class CredentialStorage extends Activity {
     private boolean confirmKeyGuard() {
         Resources res = getResources();
         boolean launched = new ChooseLockSettingsHelper(this)
-                .launchConfirmationActivity(CONFIRM_KEY_GUARD_REQUEST, null,
-                                            res.getText(R.string.credentials_install_gesture_explanation),
-                                            true);
+                .launchConfirmationActivity(CONFIRM_KEY_GUARD_REQUEST,
+                        res.getText(R.string.credentials_title), true);
         return launched;
     }