Add an NDK library variant

An NDK built library variant is needed for
clients using the NDK toolchain.
Move the Android depth buffer validation sequence
in a separate module.

Bug: 123237859
Test: Camera CTS

Change-Id: Ibf149f0be02a40de31e901cfc420f203d10e5bf3
diff --git a/README.android b/README.android
index 7a8f454..00f3c0b 100644
--- a/README.android
+++ b/README.android
@@ -6,4 +6,4 @@
 Local patches
 -------------
 - Android depth photo validation sequence "ValidateAndroidDynamicDepthBuffer()".
-
+- Add NDK library variant.