Add condition provider access to settings.

Pull NotificationAccessSettings out into a reusable base class
and reuse all of it for a new condition providers settings page.

As with notification listeners, the entire section is hidden if
no apps provide conditions.

Change-Id: Ib5273f3362e392d99647347c23a514e4590f7ac9

src/com/android/settings/Settings.java

@@ -80,6 +80,7 @@ public class Settings extends SettingsActivity {
     public static class NotificationStationActivity extends SettingsActivity { /* empty */ }
     public static class UserSettingsActivity extends SettingsActivity { /* empty */ }
     public static class NotificationAccessSettingsActivity extends SettingsActivity { /* empty */ }
+    public static class ConditionProviderSettingsActivity extends SettingsActivity { /* empty */ }
     public static class UsbSettingsActivity extends SettingsActivity { /* empty */ }
     public static class TrustedCredentialsSettingsActivity extends SettingsActivity { /* empty */ }
     public static class PaymentSettingsActivity extends SettingsActivity { /* empty */ }