TRON log important auto-fill events

Example log from
android.autofillservice.cts.LoginActivityTest#testAutoFill#testAutoFillOneDatasetAndSave
(translated from numbers of human readable string):

AUTOFILL_SESSION_STARTED
   package=android.autofillservice.cts
AUTOFILL_REQUEST
   type=TYPE_SUCCESS
   package=android.autofillservice.cts
   FIELD_AUTOFILL_SERVICE=android.autofillservice.cts
   FIELD_AUTOFILL_NUM_DATASETS=1
AUTOFILL_FILL_UI
   type=TYPE_ACTION
   package=android.autofillservice.cts
   FIELD_AUTOFILL_NUM_DATASETS=1
   FIELD_AUTOFILL_FILTERTEXT_LEN=0
AUTOFILL_DATASET_APPLIED
   package=android.autofillservice.cts
   FIELD_AUTOFILL_NUM_VALUES=2
   FIELD_AUTOFILL_NUM_VIEWS_FILLED=2
AUTOFILL_SAVE_UI
   package=android.autofillservice.cts
   FIELD_AUTOFILL_NUM_IDS=2
AUTOFILL_DATA_SAVE_REQUEST
   type=TYPE_SUCCESS
   package=android.autofillservice.cts
   FIELD_AUTOFILL_SERVICE=android.autofillservice.cts
AUTOFILL_SESSION_FINISHED
   package=android.autofillservice.cts

Test: Ran auto-fill tests and looked at event log.
Change-Id: I58aaa58e4435e7d04c8cd91878411943d3eb13de
diff --git a/core/java/android/widget/CompoundButton.java b/core/java/android/widget/CompoundButton.java
index 899a824..9dc61ab 100644
--- a/core/java/android/widget/CompoundButton.java
+++ b/core/java/android/widget/CompoundButton.java
@@ -584,14 +584,16 @@
     }
 
     @Override
-    public void autofill(AutofillValue value) {
-        if (!isEnabled()) return;
+    public boolean autofill(AutofillValue value) {
+        if (!isEnabled()) return false;
 
         if (value.isToggle()) {
             setChecked(value.getToggleValue());
         } else {
             Log.w(LOG_TAG, value + " could not be autofilled into " + this);
         }
+
+        return true;
     }
 
     @Override