Moar changes for Autofill Field Classification mechanism:

- Changed max score to float (range 0.0 - 1.0).
- Replaced getTopMatch() to getMatches().
- Created a Scorer interface with a default edit-distance implementation.
- Added a isFieldClassificationEnabled() method.

Test: atest CtsAutoFillServiceTestCases:FieldsClassificationTest
Test: atest CtsAutoFillServiceTestCases:EditDistanceScorerTest
Test: atest CtsAutoFillServiceTestCases:UserDataTest
Test: atest FrameworksCoreTests:SettingsBackupTest

Bug: 68045531

Change-Id: Ice6cbf548053b86b47980d9664a3a21219c0ff08
diff --git a/core/java/android/view/autofill/AutofillManager.java b/core/java/android/view/autofill/AutofillManager.java
index 9a99e53..4c47b89 100644
--- a/core/java/android/view/autofill/AutofillManager.java
+++ b/core/java/android/view/autofill/AutofillManager.java
@@ -1057,6 +1057,23 @@
     }
 
     /**
+     * TODO(b/67867469):
+     * - proper javadoc
+     * - mention this method in other places
+     * - unhide / remove testApi
+     * @hide
+     */
+    @TestApi
+    public boolean isFieldClassificationEnabled() {
+        try {
+            return mService.isFieldClassificationEnabled();
+        } catch (RemoteException e) {
+            e.rethrowFromSystemServer();
+            return false;
+        }
+    }
+
+    /**
      * Returns {@code true} if autofill is supported by the current device and
      * is supported for this user.
      *