Changing minSDK for launcher3 to 21 (Lollipop)

Change-Id: I421a33801886bdcccb43429b571af1ca7c6b9f55
diff --git a/build.gradle b/build.gradle
index d777e95..2efbec4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,7 +17,7 @@
 
     defaultConfig {
         applicationId "com.android.launcher3"
-        minSdkVersion 16
+        minSdkVersion 21
         targetSdkVersion 23
         versionCode 1
         versionName "1.0"