libbinder: Include stability.cpp in the Trusty NDK library

Bug: 242243245
Test: build Trusty
Change-Id: I3d449982cb3b6e5e8b40f58f1924726400a22cf0
diff --git a/libs/binder/ndk/stability.cpp b/libs/binder/ndk/stability.cpp
index ca3d5e6..39cf1c4 100644
--- a/libs/binder/ndk/stability.cpp
+++ b/libs/binder/ndk/stability.cpp
@@ -23,7 +23,7 @@
 
 using ::android::internal::Stability;
 
-#ifdef __ANDROID_VNDK__
+#if defined(__ANDROID_VNDK__) && !defined(__TRUSTY__)
 #error libbinder_ndk should only be built in a system context
 #endif