Remove debug.ld.greylist_disabled property

This property provided a way to disable the greylist, for testing
whether an app targeting < 24 still works. Instead of turning off the
greylist, though, an app developer should simply target a newer API.

(If app developers really need this property for testing, they can
still use it on versions of Android between N and R, inclusive.)

Update language to comply with Android's inclusive language guidance

See https://source.android.com/setup/contribute/respectful-code for reference

#inclusivefixit

Bug: http://b/162536543
Test: bionic-unit-tests
Change-Id: Id1eb2807fbb7436dc9ed7fe47e15b7d165a26789
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 7cfe87b..6da315e 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -207,7 +207,7 @@
   };
 
   // If you're targeting N, you don't get the greylist.
-  if (g_greylist_disabled || get_application_target_sdk_version() >= 24) {
+  if (get_application_target_sdk_version() >= 24) {
     return false;
   }