Fixed AccessPreference listener.

When an app is blacklisted, its switch toggle is disabled, but previous
the onClick() method was still being called, which would launch the data
usage screen but also call setIsWhitelist().

BUG: 27481520
Change-Id: Id8df3d65eee286d1aecb4ae2a0417d6932d91441
diff --git a/src/com/android/settings/datausage/UnrestrictedDataAccess.java b/src/com/android/settings/datausage/UnrestrictedDataAccess.java
index c8df0ba..650b0b2 100644
--- a/src/com/android/settings/datausage/UnrestrictedDataAccess.java
+++ b/src/com/android/settings/datausage/UnrestrictedDataAccess.java
@@ -227,19 +227,20 @@
             if (mEntry.icon != null) {
                 setIcon(mEntry.icon);
             }
-            setOnPreferenceClickListener( new OnPreferenceClickListener() {
+        }
 
-                @Override
-                public boolean onPreferenceClick(Preference pref) {
-                    if (mState.isDataSaverBlacklisted) {
-                        InstalledAppDetails.startAppInfoFragment(AppDataUsage.class,
-                                context.getString(R.string.app_data_usage),
-                                UnrestrictedDataAccess.this,
-                                mEntry);
-                        return false;
-                    }
-                    return true;
-                }});
+        @Override
+        protected void onClick() {
+            if (mState.isDataSaverBlacklisted) {
+                // app is blacklisted, launch App Data Usage screen
+                InstalledAppDetails.startAppInfoFragment(AppDataUsage.class,
+                        getContext().getString(R.string.app_data_usage),
+                        UnrestrictedDataAccess.this,
+                        mEntry);
+            } else {
+                // app is not blacklisted, let superclass handle toggle switch
+                super.onClick();
+            }
         }
 
         // Sets UI state based on whitelist/blacklist status.