title: Android proguard doesn't obfuscate classes
body: <p>I've build a release Android application with proguard, but after decompiling of APK I see that classes, which must be obfuscated, have normal sources. There's a part of my gradle build :</p>
  
  <pre><code>buildTypes {
      debug {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
      }
      release {
          minifyEnabled true
          proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
      }
  }
  </code></pre>
  
  <p>And here's my proguard-rules.pro file:</p>
  
  <pre><code>-dontpreverify
  -repackageclasses ''
  -allowaccessmodification
  -keepattributes *Annotation*
  
  -keep public class * extends android.app.Activity
  -keep public class * extends android.app.Application
  -keep public class * extends android.app.Service
  -keep public class * extends android.content.BroadcastReceiver
  -keep public class * extends android.content.ContentProvider
  
  -keep public class * extends android.view.View {
      public &lt;init&gt;(android.content.Context);
      public &lt;init&gt;(android.content.Context, android.util.AttributeSet);
      public &lt;init&gt;(android.content.Context, android.util.AttributeSet, int);
      public void set*(...);
  }
  
  -keepclasseswithmembers class * {
      public &lt;init&gt;(android.content.Context, android.util.AttributeSet);
  }
  
  -keepclasseswithmembers class * {
      public &lt;init&gt;(android.content.Context, android.util.AttributeSet, int);
  }
  
  -keepclassmembers class * implements android.os.Parcelable {
      static android.os.Parcelable$Creator CREATOR;
  }
  
  -keepclassmembers class **.R$* {
      public static &lt;fields&gt;;
  }
  
  -keep public class * extends android.support.v4.app.Fragment
  -keep public class * extends android.app.Fragment
  
  -keepnames class * implements java.io.Serializable
  
  -keepclassmembers class * implements java.io.Serializable {
      static final long serialVersionUID;
      private static final java.io.ObjectStreamField[] serialPersistentFields;
      !static !transient &lt;fields&gt;;
      !private &lt;fields&gt;;
      !private &lt;methods&gt;;
      private void writeObject(java.io.ObjectOutputStream);
      private void readObject(java.io.ObjectInputStream);
      java.lang.Object writeReplace();
      java.lang.Object readResolve();
  }
  
  -assumenosideeffects class android.util.Log {
      public static *** e(...);
      public static *** w(...);
      public static *** wtf(...);
      public static *** d(...);
      public static *** v(...);
  }
  
  -keepclasseswithmembernames class * {
      native &lt;methods&gt;;
  }
  -keepclassmembers class * {
      public void *ButtonClicked(android.view.View);
  }
  
  -dontwarn okio**
  -dontwarn java.lang.invoke**
  -dontwarn org.apache.commons.io**
  -dontwarn org.codehaus**
  -keep public class java.nio**
  -dontwarn android.support.v4.**
  -keep class android.support.v4.** { *; }
  -dontwarn android.support.v7.**
  -keep class android.support.v7.** { *; }
  -keep class net.sqlcipher.** { *; }
  
  -keep class net.sqlcipher.database.** { *; }
  
  -keep class retrofit2.** { *; }
  -keepattributes Signature
  -keepattributes Exceptions
  -keepclasseswithmembers class * {
      @retrofit2.http.* &lt;methods&gt;;
  }
  -keep class com.squareup.okhttp.** { *; }
  -keep interface com.squareup.okhttp.** { *; }
  -keep class com.google.gson.** { *; }
  -keep class com.google.inject.* { *; }
  -keep class org.apache.http.** { *; }
  -keep class org.apache.james.mime4j.** { *; }
  -keep class javax.inject.** { *; }
  -keepclassmembernames interface * {
      @retrofit.http.* &lt;methods&gt;;
  }
  
  -keep class sun.misc.Unsafe { *; }
  -keep public class !com.vidal.cardio.datas.MySQLCipherOpenHelper { *; }
  -keep public class !com.vidal.cardio.datas.SCLcipherOpenHelper { *; }
  </code></pre>
  
  <p>Well, I've expected that <code>MySQLCipherOpenHelper</code> and <code>SCLcipherOpenHelper</code> will be obfuscated, but actually they don't. Maybe there's a mistake in proguard-rules.pro?</p>