Add super_image module type and create super image module in fsgen

fsgen processes the variables exported from make and create
the super image module. This module generates the misc-info.txt,
which is used by build_super_image.py to build the super image.

Test: CI
Bug: 376726109
Change-Id: I74a3e68d697704f36a770b3c83e5f8821b3ac128
diff --git a/fsgen/Android.bp b/fsgen/Android.bp
index e8065f3..365d954 100644
--- a/fsgen/Android.bp
+++ b/fsgen/Android.bp
@@ -17,6 +17,7 @@
         "filesystem_creator.go",
         "fsgen_mutators.go",
         "prebuilt_etc_modules_gen.go",
+        "super_img.go",
         "util.go",
         "vbmeta_partitions.go",
     ],