RESTRICT AUTOMERGE Ignore weak symbol difference in libbinder ABI check

The diff_flags make the ABI checker ignore the weak symbol difference
caused by PGO and -DBINDER_RPC_DEV_SERVERS.

Test: make libbinder.vendor
Bug: 230079120
Change-Id: I55878c1b2653b33edd61756e269c86a110016351
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 63d87da..d8d2cf2 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -226,6 +226,10 @@
     ],
 
     afdo: true,
+
+    header_abi_checker: {
+        diff_flags: ["-allow-adding-removing-weak-symbols"],
+    },
 }
 
 cc_defaults {