Show module type in a module section of the Android-TARGET.mk

The first line of each section will be
```
include $(CLEAR_VARS)  # <module type>
...
```

Bug: 257037252
Test: treehugger
Change-Id: Iba586155b682fe4e1e5817d8397eda8f9d9c8789
diff --git a/sysprop/sysprop_library.go b/sysprop/sysprop_library.go
index 1f0d28d..0edbb7c 100644
--- a/sysprop/sysprop_library.go
+++ b/sysprop/sysprop_library.go
@@ -336,8 +336,8 @@
 		Custom: func(w io.Writer, name, prefix, moduleDir string, data android.AndroidMkData) {
 			// sysprop_library module itself is defined as a FAKE module to perform API check.
 			// Actual implementation libraries are created on LoadHookMutator
-			fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)")
-			fmt.Fprintf(w, "LOCAL_MODULE := %s\n", m.Name())
+			fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)", " # sysprop.syspropLibrary")
+			fmt.Fprintln(w, "LOCAL_MODULE :=", m.Name())
 			data.Entries.WriteLicenseVariables(w)
 			fmt.Fprintf(w, "LOCAL_MODULE_CLASS := FAKE\n")
 			fmt.Fprintf(w, "LOCAL_MODULE_TAGS := optional\n")