Adjust ACSD APIs

* ChangeId DROP_CLOSE_SYSTEM_DIALOGS doesn't need to be @TestApi.
* BROADCAST_CLOSE_SYSTEM_DIALOGS permission needs to be @SystemApi given
its protectionLevel

Bug: 181593849
Test: Builds
Test: atest CloseSystemDialogsTest
Change-Id: I6cbbc4a396f920e6cc60299ba827c76158e2e7cf
4 files changed