Make all binder NDK APIs available on the host.

Test: treehugger
Change-Id: Icd65cf89a67ba435000d9c8464c3d8a61447a33b
diff --git a/libs/binder/ndk/Android.bp b/libs/binder/ndk/Android.bp
index 62a0f9f..c0ea6d7 100644
--- a/libs/binder/ndk/Android.bp
+++ b/libs/binder/ndk/Android.bp
@@ -22,6 +22,8 @@
             cflags: [
                 "-D__INTRODUCED_IN(n)=",
                 "-D__assert(a,b,c)=",
+                // We want all the APIs to be available on the host.
+                "-D__ANDROID_API__=10000",
             ],
         },
     },