DO NOT MERGE Add flag to control dynamic shortcuts experment

Also fix the format of pull to refresh experiment flag

Bug 30630964
Bug 30189449

Change-Id: Ib297cee400b5e864a6ca71566c3d4182cb041226
(cherry picked from commit 4846b68b921514384e7701ff96d6d43b9fd2210a)
diff --git a/src/com/android/contacts/common/Experiments.java b/src/com/android/contacts/common/Experiments.java
index c811e27..7d318af 100644
--- a/src/com/android/contacts/common/Experiments.java
+++ b/src/com/android/contacts/common/Experiments.java
@@ -20,6 +20,11 @@
  */
 public final class Experiments {
 
+    /**
+     * Experiment to enable dynamic strequent shortcuts.
+     */
+    public static final String DYNAMIC_SHORTCUTS = "Shortcuts__dynamic_shortcuts";
+
     private Experiments() {
     }
 }