Fix some proguard rules to fix tests

Don't strip some ContactsCommon classes to allow tests
to run.

Change-Id: Ic057237dffc68663a4da517efc150da334a3574a
diff --git a/proguard.flags b/proguard.flags
index 185d5eb..6eed998 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -5,6 +5,8 @@
   public void *(android.view.MenuItem);
 }
 
+-keep class com.android.contacts.common.** { *;}
+
 # Any class or method annotated with NeededForTesting or NeededForReflection.
 -keep @com.android.contacts.common.testing.NeededForTesting class *
 -keepclassmembers class * {