Migrate libcamera2ndk to ndk_library.

Test: make checkbuild tests
Bug: http://b/30465923
Change-Id: Iab800fd20beeef64250abc7d1c966d12fa8bfbb5
diff --git a/Android.bp b/Android.bp
index 6fd6c72..0990db6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,12 @@
+ndk_headers {
+    name: "libcamera2ndk_headers",
+    from: "include/camera/ndk/",
+    to: "camera",
+    srcs: ["include/camera/ndk/**/*.h"],
+}
+
 subdirs = [
+    "camera/ndk",
     "media/libmedia",
     "media/libstagefright/foundation",
 ]