Add version in about screen

app/build.gradle

@@ -39,11 +39,14 @@ android {
         debug {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+            versionNameSuffix '.debug'
+            resValue 'string', 'app_version', "${defaultConfig.versionName}${versionNameSuffix} (${defaultConfig.versionCode})"
         }
         release {
             signingConfig signingConfigs.releaseConfig
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+            resValue 'string', 'app_version', "${defaultConfig.versionName} (${defaultConfig.versionCode})"
         }
     }
 

app/src/main/res/layout/dialog_about.xml

@@ -41,6 +41,16 @@
             android:textSize="36sp"
             app:fontFamily="sans-serif-condensed" />
 
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:gravity="center"
+            android:text="@string/app_version"
+            android:textColor="@android:color/white"
+            android:textSize="18sp"
+            app:fontFamily="sans-serif-condensed" />
+
         <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"