proguard: preserve ezvcard properties

Change-Id: I6467b6f50b36ec4e6f3f2b46e1c594d2ad66e847

ring-android/app/build.gradle

@@ -8,8 +8,8 @@ android {
     defaultConfig {
         minSdkVersion 21
         targetSdkVersion 28
-        versionCode 163
-        versionName "20190525-5"
+        versionCode 164
+        versionName "20190525-6"
     }
 
     sourceSets {

ring-android/app/proguard-rules.pro

@@ -5,6 +5,7 @@
 -keepattributes Signature
 
 -keep class android.support.v7.widget.LinearLayoutManager { *; }
+-keep,includedescriptorclasses class androidx.core.content.FileProvider { *; }
 
 -keep,includedescriptorclasses class cx.ring.** { *; }
 -keepclassmembers class cx.ring.** { *; }
@@ -35,13 +36,14 @@
 -dontwarn freemarker.**
 
 # EZVcard
--dontwarn ezvcard.io.json.JCardModule
+-dontwarn ezvcard.io.json.**
 -keep,includedescriptorclasses class ezvcard.io.json.JCardModule { *; }
 -keepclassmembers class ezvcard.io.json.JCardModule { *; }
 -keep,includedescriptorclasses enum ezvcard.io.json.JCardModule { *; }
 -keepclassmembers enum ezvcard.io.json.JCardModule { *; }
 -keep,includedescriptorclasses interface ezvcard.io.json.JCardModule { *; }
 -keepclassmembers interface ezvcard.io.json.JCardModule { *; }
+-keep class ezvcard.property.** { *; }
 
 # barcodescanner
 -keep,includedescriptorclasses class com.journeyapps.barcodescanner.** { *; }

ring-android/libringclient/src/main/java/cx/ring/utils/VCardUtils.java

@@ -161,14 +161,14 @@ public final class VCardUtils {
      */
     private static VCard loadFromDisk(String path) {
         try {
-            if (StringUtils.isEmpty(path)) {
-                // Log.d(TAG, "Empty file or error with the context");
+            if (path == null || path.isEmpty()) {
+                Log.d(TAG, "Empty file or error with the context");
                 return null;
             }
 
             File vcardPath = new File(path);
             if (!vcardPath.exists()) {
-                // Log.d(TAG, "vcardPath not exist " + vcardPath);
+                Log.d(TAG, "vcardPath not exist " + vcardPath);
                 return null;
             }