version bump 0.8.4 (#227)

Corona-Warn-App/build.gradle

@@ -33,8 +33,8 @@ android {
         applicationId 'de.rki.coronawarnapp'
         minSdkVersion 23
         targetSdkVersion 29
-        versionCode 10
-        versionName "0.8.3"
+        versionCode 11
+        versionName "0.8.4"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 
         buildConfigField "String", "DOWNLOAD_CDN_URL", "\"$DOWNLOAD_CDN_URL\""