android [nfc]: Add a TODO(#855) for removing a lint suppression

Added in 3013e07, a file_picker package upgrade; #855 is for
dropping the file_picker dependency.

Author: chrisbobbe

android/app/lint-baseline.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <issues format="6" by="lint 8.5.2" type="baseline" client="gradle" dependencies="false" name="AGP (8.5.2)" variant="all" version="8.5.2">
 
+    <!--TODO(#855) see if this is no longer needed-->
     <issue
         id="InvalidPackage"
         message="Invalid package reference in library; not included in Android: `javax.xml.stream`. Referenced from `org.apache.tika.utils.XMLReaderUtils`.">