Change minSdkVersion of ContactsTests to 21

Bug 27244680
Bug 26818072
Bug 25629359

Change-Id: I903455c189b2ac3419e80b38cc04d1fc7210167e
diff --git a/tests/AndroidManifest.xml b/tests/AndroidManifest.xml
index 5666b18..29da53c 100644
--- a/tests/AndroidManifest.xml
+++ b/tests/AndroidManifest.xml
@@ -18,7 +18,7 @@
     package="com.android.contacts.tests">
 
     <uses-sdk
-        android:minSdkVersion="23"
+        android:minSdkVersion="21"
         android:targetSdkVersion="23" />
 
     <uses-permission android:name="android.permission.READ_CONTACTS" />