Move pgo rules to afdo

Test: presubmit
Change-Id: Ic590208e2163e7703c3493dbe435cbe2ac7cce33
diff --git a/Android.bp b/Android.bp
index bbb3d8d..2fd04d3 100644
--- a/Android.bp
+++ b/Android.bp
@@ -164,16 +164,9 @@
     whole_static_libs: ["libc++_static"],
     stl: "none",
 
-    pgo: {
-        sampling: true,
-    },
+    afdo: true,
 
     target: {
-        android: {
-            pgo: {
-                profile_file: "libc++/libc++.profdata",
-            },
-        },
         darwin: {
             unexported_symbols_list: "lib/libc++unexp.exp",
             force_symbols_not_weak_list: "lib/notweak.exp",