Target SDK 19, fix build.

Change ag/371791 depends on SDK 19.

Change-Id: I8411f55063c8899f65cb85ddbf45adab564de808
diff --git a/Android.mk b/Android.mk
index e22d53c..3b1a244 100644
--- a/Android.mk
+++ b/Android.mk
@@ -32,7 +32,7 @@
 LOCAL_PROTOC_OPTIMIZE_TYPE := nano
 LOCAL_PROTOC_FLAGS := --proto_path=$(LOCAL_PATH)/protos/
 
-LOCAL_SDK_VERSION := 17
+LOCAL_SDK_VERSION := 19
 
 LOCAL_PACKAGE_NAME := Launcher3
 #LOCAL_CERTIFICATE := shared