[incremental/pm] app states and transitions

Based on go/incremental-states-design with basic
setter/getters.

Defines IncrementalStates class which handles state transitions.

New (internal) Intent actions: PACKAGE_FULLY_LOADED, PACKAGE_STARTABLE,
PACKAGE_UNSTARTABLE.

BUG: 168043976
Test: unit tests
Change-Id: I7b0ec2dd9f028ee620a9307a1e71ddf12ea5a9af
diff --git a/services/incremental/IncrementalService.h b/services/incremental/IncrementalService.h
index d820417..504c02a 100644
--- a/services/incremental/IncrementalService.h
+++ b/services/incremental/IncrementalService.h
@@ -200,6 +200,7 @@
 
     private:
         binder::Status onStatusChanged(MountId mount, int newStatus) final;
+        binder::Status reportStreamHealth(MountId mount, int newStatus) final;
 
         sp<content::pm::IDataLoader> getDataLoader();