Use openfortesting for new Kotlin files needed in tests

owncloudComLibrary/build.gradle

@@ -2,12 +2,19 @@ apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-kapt'
 
+apply plugin: 'kotlin-allopen'
+
 dependencies {
     api 'com.squareup.okhttp3:okhttp:3.12.0'
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion"
     api 'com.gitlab.ownclouders:dav4android:oc_support_1.0.1'
 }
 
+allOpen {
+    // allows mocking for classes w/o directly opening them for release builds
+    annotation 'com.owncloud.android.lib.testing.OpenClass'
+}
+
 android {
     compileSdkVersion 28
 

owncloudComLibrary/src/debug/java/com/owncloud/android/lib/testing/OpenForTesting.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.owncloud.android.lib.testing
+
+/**
+ * This annotation allows us to open some classes for mocking purposes while they are final in
+ * release builds.
+ */
+@Target(AnnotationTarget.ANNOTATION_CLASS)
+annotation class OpenClass
+
+/**
+ * Annotate a class with [OpenForTesting] if you want it to be extendable in debug builds.
+ */
+@OpenClass
+@Target(AnnotationTarget.CLASS)
+annotation class OpenForTesting

owncloudComLibrary/src/main/java/com/owncloud/android/lib/resources/status/OwnCloudVersion.kt

@@ -27,7 +27,9 @@ package com.owncloud.android.lib.resources.status
 
 import android.os.Parcel
 import android.os.Parcelable
+import com.owncloud.android.lib.testing.OpenForTesting
 
+@OpenForTesting
 class OwnCloudVersion(version: String) : Comparable<OwnCloudVersion>, Parcelable {
 
     // format is in version
@@ -36,7 +38,7 @@ class OwnCloudVersion(version: String) : Comparable<OwnCloudVersion>, Parcelable
     // ie version 2.0.3 will be stored as 0x02000300
     private var mVersion: Int = 0
     var isVersionValid: Boolean = false
-        private set
+        set
 
     val version: String
         get() = if (isVersionValid) {