Tie ContextualWifiSlice to UI instead of garbage collector

- Introduce a static long in SliceFeatureProvider that updates once
  every "session". A session is when user is in an UI (screen rotation,
  going to subpage, etc does not break the continuation of session).

- Use session token in ContextualWifiSlice to determine when to refresh,
  instead of relying on WeakHashMap from CustomSliceManager.
  WeakHashMap can be cleaned up at any time by gc so it doesn't match
  what we want on the UI.

- Also as a side fix, merged CustomSliceManager into
  SliceFeatureProvider.

Fixes: 123937830
Test: robo
Change-Id: I199bceceb208b99a32f3f08e624787b5a03e73a9

src/com/android/settings/slices/SettingsSliceProvider.java

@@ -117,9 +117,6 @@ public class SettingsSliceProvider extends SliceProvider {
 
     private static final KeyValueListParser KEY_VALUE_LIST_PARSER = new KeyValueListParser(',');
 
-    @VisibleForTesting
-    CustomSliceManager mCustomSliceManager;
-
     @VisibleForTesting
     SlicesDatabaseAccessor mSlicesDatabaseAccessor;
 
@@ -140,15 +137,15 @@ public class SettingsSliceProvider extends SliceProvider {
         mSlicesDatabaseAccessor = new SlicesDatabaseAccessor(getContext());
         mSliceDataCache = new ConcurrentHashMap<>();
         mSliceWeakDataCache = new WeakHashMap<>();
-        mCustomSliceManager = FeatureFactory.getFactory(
-                getContext()).getSlicesFeatureProvider().getCustomSliceManager(getContext());
         return true;
     }
 
     @Override
     public void onSlicePinned(Uri sliceUri) {
         if (CustomSliceRegistry.isValidUri(sliceUri)) {
-            final CustomSliceable sliceable = mCustomSliceManager.getSliceableFromUri(sliceUri);
+            final Context context = getContext();
+            final CustomSliceable sliceable = FeatureFactory.getFactory(context)
+                    .getSlicesFeatureProvider().getSliceableFromUri(context, sliceUri);
             final IntentFilter filter = sliceable.getIntentFilter();
             if (filter != null) {
                 registerIntentToUri(filter, sliceUri);
@@ -195,9 +192,10 @@ public class SettingsSliceProvider extends SliceProvider {
             // Before adding a slice to {@link CustomSliceManager}, please get approval
             // from the Settings team.
             if (CustomSliceRegistry.isValidUri(sliceUri)) {
-                final CustomSliceable sliceable = mCustomSliceManager.getSliceableFromUri(
-                        sliceUri);
-                return sliceable.getSlice();
+                final Context context = getContext();
+                return FeatureFactory.getFactory(context)
+                        .getSlicesFeatureProvider().getSliceableFromUri(context, sliceUri)
+                        .getSlice();
             }
 
             if (CustomSliceRegistry.WIFI_CALLING_URI.equals(sliceUri)) {