Add isSliceable API to BasePrefController

Only support explicitly approved Settings Slices,
dictated by controllers which return true for the new
method isSliceable.

Updating the supported settings to a whitelist means that
the method to return all available slices must be updated,
and checking slicability when we index slices.

Test: robotests
Change-Id: I85848c2cdf3e151fa94b33dd1dc5c0374ef94b5b
Merged-In: Ib2b9690cdd0036b5cc4a1cb846c52bce7c824ab9
Fixes: 79779103

tests/robotests/src/com/android/settings/slices/FakePreferenceController.java

@@ -35,4 +35,9 @@ public class FakePreferenceController extends BasePreferenceController {
     public int getSliceType() {
         return SliceData.SliceType.SLIDER;
     }
+
+    @Override
+    public boolean isSliceable() {
+        return true;
+    }
 }

tests/robotests/src/com/android/settings/slices/SlicesDatabaseAccessorTest.java

@@ -70,6 +70,11 @@ public class SlicesDatabaseAccessorTest {
         mAccessor = spy(new SlicesDatabaseAccessor(mContext));
         mDb = SlicesDatabaseHelper.getInstance(mContext).getWritableDatabase();
         SlicesDatabaseHelper.getInstance(mContext).setIndexedState();
+
+        // Register the fake a11y Service
+        ShadowAccessibilityManager shadowAccessibilityManager = Shadow.extract(
+                RuntimeEnvironment.application.getSystemService(AccessibilityManager.class));
+        shadowAccessibilityManager.setInstalledAccessibilityServiceList(new ArrayList<>());
     }
 
     @After
@@ -173,10 +178,6 @@ public class SlicesDatabaseAccessorTest {
     public void getSliceKeys_indexesDatabase() {
         // Force new indexing
         Locale.setDefault(new Locale("ca"));
-        // Register the fake a11y Service
-        ShadowAccessibilityManager shadowAccessibilityManager = Shadow.extract(
-                RuntimeEnvironment.application.getSystemService(AccessibilityManager.class));
-        shadowAccessibilityManager.setInstalledAccessibilityServiceList(new ArrayList<>());
         final SearchFeatureProvider provider = new SearchFeatureProviderImpl();
         final SlicesFeatureProvider sliceProvider = spy(new SlicesFeatureProviderImpl());
         final FakeFeatureFactory factory = FakeFeatureFactory.setupForTest();