Build all samples against SDK.

Change-Id: I9ea35c07a7f9d2e2a42d952101e99528fd68fb6c
diff --git a/samples/XmlAdapters/Android.mk b/samples/XmlAdapters/Android.mk
index a2cad3a..e12ce57 100644
--- a/samples/XmlAdapters/Android.mk
+++ b/samples/XmlAdapters/Android.mk
@@ -10,6 +10,8 @@
 
 LOCAL_PROGUARD_ENABLED := disabled
 
+LOCAL_SDK_VERSION := current
+
 include $(BUILD_PACKAGE)
 
 # Use the following include to make our test apk.