enable proguard

// FREEBIE

build.gradle

@@ -82,6 +82,17 @@ android {
     }
 
     android {
+        buildTypes {
+            debug {
+                runProguard true
+                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard.cfg'
+            }
+            release {
+                runProguard true
+                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard.cfg'
+            }
+        }
+
         sourceSets {
             main {
                 manifest.srcFile 'AndroidManifest.xml'

proguard.cfg

@@ -0,0 +1,31 @@
+-dontobfuscate
+
+## Support
+
+-keep class android.support.v4.app.** { *; }
+-keep interface android.support.v4.app.** { *; }
+
+-keep class android.support.v7.internal.** { *; }
+-keep interface android.support.v7.internal.** { *; }
+-keep class android.support.v7.** { *; }
+-keep interface android.support.v7.** { *; }
+-keep public class * extends android.support.v7.app.ActionBarActivity { *; }
+-keep class android.support.v7.widget.** { *; }
+-keepattributes *Annotation*
+
+## Protobuf
+
+-keep class com.google.protobuf.** { *; }
+
+## GSON
+
+# removes such information by default, so configure it to keep all of it.
+-keepattributes Signature
+
+# For using GSON @Expose annotation
+-keepattributes *Annotation*
+
+# Gson specific classes
+-keep class sun.misc.Unsafe { *; }
+#-keep class com.google.gson.stream.** { *; }
+