ui/Interpolator/template-params.xml: Set minSdk=21

Change minSdk for Interpolator sample from L to 21.

Change-Id: I4fd42c82c123dc1a17ebfe6ed5330cda5cca8832
diff --git a/ui/Interpolator/template-params.xml b/ui/Interpolator/template-params.xml
index 6549b44..268ee8a 100644
--- a/ui/Interpolator/template-params.xml
+++ b/ui/Interpolator/template-params.xml
@@ -23,7 +23,7 @@
     <package>com.example.android.interpolator</package>
 
     <!-- change minSdk if needed-->
-    <minSdk>L</minSdk>
+    <minSdk>21</minSdk>
 
     <strings>
         <intro>