Send more sparse groups since autogroup threshold has changed

Test: NotificationManagerTest
Bug: 402725724
Flag: com.android.server.notification.notification_force_group_singletons
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:3d854e5fb47a652bab9c6a8bce5bd029959cecb9)
Merged-In: I93375eaee852c3c6c8d24f0ab408cd281c39ae0a
Change-Id: I93375eaee852c3c6c8d24f0ab408cd281c39ae0a
1 file changed