[play] Add a new attribute type for GMS Play in order to distinguish with the old M0 flow.

Bug: 260712395
Test: wwlogcat https://paste.googleplex.com/5204101439684608
Flag: ENABLE_SEARCH_UNINSTALLED_APPS. OFF
Change-Id: I5dc75b7aef9cd778c59167347500b923626e4953
diff --git a/protos/launcher_atom.proto b/protos/launcher_atom.proto
index bf84820..55301ff 100644
--- a/protos/launcher_atom.proto
+++ b/protos/launcher_atom.proto
@@ -135,7 +135,7 @@
   }
 }
 
-// Next value 44
+// Next value 45
 enum Attribute {
   option allow_alias = true;
 
@@ -173,6 +173,7 @@
   ALL_APPS_SEARCH_RESULT_SLICE = 19;
   ALL_APPS_SEARCH_RESULT_WIDGETS = 20;
   ALL_APPS_SEARCH_RESULT_PLAY = 21;
+  ALL_APPS_SEARCH_RESULT_PLAY_GMS = 44;
   ALL_APPS_SEARCH_RESULT_FALLBACK = 22;
   ALL_APPS_SEARCH_RESULT_SUGGEST = 22 [deprecated = true];
   ALL_APPS_SEARCH_RESULT_ASSISTANT = 23;