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/filesystem/Android.bp b/filesystem/Android.bp
index bbb3ea7..127faa7 100644
--- a/filesystem/Android.bp
+++ b/filesystem/Android.bp
@@ -25,6 +25,7 @@
         "fsverity_metadata.go",
         "logical_partition.go",
         "raw_binary.go",
+        "super_image.go",
         "system_image.go",
         "vbmeta.go",
         "testing.go",