Add licenses to ndk_headers.

Test: make ndk
Bug: None
Change-Id: Ia113ea42b1d62d87dfbb2fc456428c7db50a98f1
diff --git a/Android.bp b/Android.bp
index 086a2c6..cd05b21 100644
--- a/Android.bp
+++ b/Android.bp
@@ -3,6 +3,7 @@
     from: "include/android",
     to: "android",
     srcs: ["include/android/**/*.h"],
+    license: "NOTICE",
 }
 
 subdirs = [