Remove gBn/sConstructorMap from headers.

Prebuilts that include toBinder() should no longer
link to gBnConstructorMap after rebuild.

After prebuilts are updated, symbols (in Static.cpp and
HidlPassthroughSupport.cpp) can be removed as well.

Test: walleye boots
Test: HAL def libs that link to libhidltransport no longer
      links to gBnConstructorMap / gBsConstructorMap.

Bug: 69122224
Change-Id: I6554a98a3068f9595666b7131df310e200551e45
diff --git a/transport/include/hidl/HidlBinderSupport.h b/transport/include/hidl/HidlBinderSupport.h
index 9759af1..55003cc 100644
--- a/transport/include/hidl/HidlBinderSupport.h
+++ b/transport/include/hidl/HidlBinderSupport.h
@@ -332,10 +332,7 @@
         if (sBnObj == nullptr) {
             auto func = details::getBnConstructorMap().get(myDescriptor, nullptr);
             if (!func) {
-                func = details::gBnConstructorMap.get(myDescriptor, nullptr);
-                if (!func) {
-                    return nullptr;
-                }
+                return nullptr;
             }
 
             sBnObj = sp<IBinder>(func(static_cast<void*>(ifacePtr)));