Changing minSDK for launcher3 to 21 (Lollipop)

Change-Id: I421a33801886bdcccb43429b571af1ca7c6b9f55
diff --git a/Android.mk b/Android.mk
index b080da2..dc43f7e 100644
--- a/Android.mk
+++ b/Android.mk
@@ -44,6 +44,7 @@
     --extra-packages android.support.v7.recyclerview \
 
 LOCAL_SDK_VERSION := current
+LOCAL_MIN_SDK_VERSION := 21
 LOCAL_PACKAGE_NAME := Launcher3
 LOCAL_OVERRIDES_PACKAGES := Home Launcher2