Workaround for Samsung Android 4.2 bug

OpenKeychain/build.gradle

@@ -106,6 +106,13 @@ android {
         sourceCompatibility JavaVersion.VERSION_1_7
         targetCompatibility JavaVersion.VERSION_1_7
     }
+    
+    buildTypes {
+        release {
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
 
     /*
      * To sign release build, create file gradle.properties in ~/.gradle/ with this content:

OpenKeychain/proguard-rules.pro

@@ -0,0 +1,26 @@
+# Add project specific ProGuard rules here.
+# You can edit the include path and order by changing the proguardFiles
+# directive in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+
+# Workaround for Samsung Android 4.2 bug
+# https://code.google.com/p/android/issues/detail?id=78377
+# https://code.google.com/p/android/issues/detail?id=78377#c188
+-keepattributes **
+-keep class !android.support.v7.internal.view.menu.**,** {*;}
+-dontpreverify
+-dontoptimize
+-dontshrink
+-dontwarn **