Revert "Move /default.prop to /system/etc/prop.default"

This reverts commit fad00e43186fb699c924e436f4cc61a88b055ed2.

init fails to read default.prop under recovery:
init: Couldn't load properties from /default.prop: Too many symbolic links encountered

Bug: 62525809
Change-Id: I133e9025693e3e01278ec73c8d08860fc89d314b
diff --git a/tools/post_process_props.py b/tools/post_process_props.py
index 9355e4b..83c6f9a 100755
--- a/tools/post_process_props.py
+++ b/tools/post_process_props.py
@@ -35,7 +35,7 @@
 def mangle_default_prop_override(prop):
   pass
 
-# Put the modifications that you need to make into the /system/etc/prop.default into this
+# Put the modifications that you need to make into the /default.prop into this
 # function. The prop object has get(name) and put(name,value) methods.
 def mangle_default_prop(prop):
   # If ro.debuggable is 1, then enable adb on USB by default
@@ -122,8 +122,7 @@
   elif (filename.endswith("/vendor/default.prop") or
         filename.endswith("/odm/default.prop")):
     mangle_default_prop_override(properties)
-  elif (filename.endswith("/default.prop") or # legacy
-        filename.endswith("/prop.default")):
+  elif filename.endswith("/default.prop"):
     mangle_default_prop(properties)
   else:
     sys.stderr.write("bad command line: " + str(argv) + "\n")