Enable AutoFDO for server_configurable_flags

This allows compiler to perform better optimization using profiles
gathered from users.

Test: presubmit
Change-Id: Ica7b6d746d75fa0628bc7c6bbdc723aec194f5d9
diff --git a/libflags/Android.bp b/libflags/Android.bp
index 61b3e2b..93ab592 100644
--- a/libflags/Android.bp
+++ b/libflags/Android.bp
@@ -22,6 +22,7 @@
         "//apex_available:anyapex",
     ],
     min_sdk_version: "29",
+    afdo: true,
 }
 
 // Tests