Add support for flagging xml and png files

This extends the previous change that added the ability to flag resource
directories so that xml and png files are now supported.

Test: Automated
Bug: 329436914
Flag: EXEMPT Aconfig not supported on host tools
Change-Id: I9f2b6b15ba0078ea33188f1a554377784cff9786
diff --git a/tools/aapt2/ResourcesInternal.proto b/tools/aapt2/ResourcesInternal.proto
index b0ed3da3..f4735a2 100644
--- a/tools/aapt2/ResourcesInternal.proto
+++ b/tools/aapt2/ResourcesInternal.proto
@@ -49,4 +49,9 @@
 
   // Any symbols this file auto-generates/exports (eg. @+id/foo in an XML file).
   repeated Symbol exported_symbol = 5;
+
+  // The status of the flag the file is behind if any
+  uint32 flag_status = 6;
+  bool flag_negated = 7;
+  string flag_name = 8;
 }