Support squashfs in map_file_generator

Test: th
Bug: 286870582
Change-Id: I0bc0ddab51939c2aea3882a6faa63e37c675e641
diff --git a/Android.bp b/Android.bp
index a466f93..efcd4db 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1338,4 +1338,7 @@
         "libsparse",
         "update_metadata-protos",
     ],
+    required: [
+        "unsquashfs",
+    ],
 }