Add "filesRoot" path to Android provider paths xml

(cherry picked from commit ac04ff7becfa31388c8bcfe725d71f0c7ec65c94)

platform/android/java/lib/res/xml/godot_provider_paths.xml

@@ -1,6 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <paths xmlns:android="http://schemas.android.com/apk/res/android">
 
+	<files-path
+		name="filesRoot"
+		path="/" />
+
 	<external-path
 		name="public"
 		path="." />