sdk doc change: Added KeyChain API Demo

Change-Id: Ib2b751a9de485359705b243d2c70e5f8f2c8ab3c
diff --git a/samples/KeyChainDemo/Android.mk b/samples/KeyChainDemo/Android.mk
new file mode 100644
index 0000000..a607e95
--- /dev/null
+++ b/samples/KeyChainDemo/Android.mk
@@ -0,0 +1,16 @@
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE_TAGS := samples
+
+# Only compile source java files in this apk.
+LOCAL_SRC_FILES := $(call all-java-files-under, src)
+
+LOCAL_PACKAGE_NAME := KeyChainDemo
+
+LOCAL_SDK_VERSION := current
+
+include $(BUILD_PACKAGE)
+
+# Use the following include to make our test apk.
+include $(call all-makefiles-under,$(LOCAL_PATH))