Cache aconfig flag for NAH refactoring

 Prevent NPE in NMS to allow advancing to trunkfood
 Proper fix in: cl/579845063 for GMSCore

Test: atest NotificationAttentionHelperTest
Test: atest NotificationManagerServiceTest

Bug: 291907312
Bug: 270456865
Bug: 308456356
Change-Id: I73f89c4a2df4c35093cfb5d24b38e96385268a8f
1 file changed