proguard: preserve ezvcard properties

Change-Id: I6467b6f50b36ec4e6f3f2b46e1c594d2ad66e847
diff --git a/ring-android/app/build.gradle b/ring-android/app/build.gradle
index 262dea9..99703e8 100644
--- a/ring-android/app/build.gradle
+++ b/ring-android/app/build.gradle
@@ -8,8 +8,8 @@
     defaultConfig {
         minSdkVersion 21
         targetSdkVersion 28
-        versionCode 163
-        versionName "20190525-5"
+        versionCode 164
+        versionName "20190525-6"
     }
 
     sourceSets {