Replacing hotseat icon to an appropriate system app

> During backupi, store the hotseat target app type, based on some predefined
common system apps
> During restore, save this app type in the restore flag, if it is a hotseat app
> During first launcher load, if an app is not being restored, try to replace it
with an appropriate replacement for that type, otherwise delete it.

Bug: 18764649
Change-Id: Ic49e40bd707bd8d7de18bbab8b1e58a0a36426a2
diff --git a/protos/backup.proto b/protos/backup.proto
index 44c4b09..09330ee 100644
--- a/protos/backup.proto
+++ b/protos/backup.proto
@@ -72,6 +72,17 @@
 }
 
 message Favorite {
+  // Type of the app, this target represents
+  enum TargetType {
+    TARGET_NONE = 0;
+    TARGET_PHONE = 1;
+    TARGET_MESSENGER = 2;
+    TARGET_EMAIL = 3;
+    TARGET_BROWSER = 4;
+    TARGET_GALLERY = 5;
+    TARGET_CAMERA = 6;
+  }
+
   required int64 id = 1;
   required int32 itemType = 2;
   optional string title = 3;
@@ -90,6 +101,7 @@
   optional string iconPackage = 16;
   optional string iconResource = 17;
   optional bytes icon = 18;
+  optional TargetType targetType = 19 [default = TARGET_NONE];
  }
 
 message Screen {