Build Aosp and GoogleContacts using Gradle

Changes needed to build Contacts and GoogleContacts
using gradle

Test: Built AOSP, Google and OEM contacts apps
  Ran tests (some failures still need to be looked at)

Bug: 34127945
Change-Id: Ia1620d11c14e8e558af706a4eee79a6a230abd59
diff --git a/proguard.flags b/proguard.flags
index 6278c61..f586b72 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -1,3 +1,5 @@
+-ignorewarnings
+
 -keep class com.android.contacts.model.Sources {
   public <init>(...);
 }
@@ -9,9 +11,6 @@
   public void *(android.view.MenuItem);
 }
 
-# Feature highlight library.  See b/29877098
--keep class com.google.android.libraries.material.featurehighlight.** { *; }
-
 # Needed for tests
 -keep class com.android.contacts.compat.CompatUtils { *; }
 -keep class com.android.contacts.Collapser { *; }