JDK8, lint fixing (#2888)

* Use Kotlin JDK8

* Satisfy a ton of lints

* Run res/layout files (and manifest) through reformatter

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupManager.kt

@@ -128,7 +128,7 @@ class BackupManager(val context: Context, version: Int = CURRENT_VERSION) {
         val categoryEntries = JsonArray()
 
         // Add value's to root
-        root[Backup.VERSION] = Backup.CURRENT_VERSION
+        root[Backup.VERSION] = CURRENT_VERSION
         root[Backup.MANGAS] = mangaEntries
         root[CATEGORIES] = categoryEntries
 
@@ -303,8 +303,8 @@ class BackupManager(val context: Context, version: Int = CURRENT_VERSION) {
     fun restoreChapterFetchObservable(source: Source, manga: Manga, chapters: List<Chapter>): Observable<Pair<List<Chapter>, List<Chapter>>> {
         return source.fetchChapterList(manga)
                 .map { syncChaptersWithSource(databaseHelper, it, manga, source) }
-                .doOnNext {
-                    if (it.first.isNotEmpty()) {
+                .doOnNext { pair ->
+                    if (pair.first.isNotEmpty()) {
                         chapters.forEach { it.manga_id = manga.id }
                         insertChapters(chapters)
                     }

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt

@@ -164,7 +164,7 @@ class BackupRestoreService : Service() {
      * @return the start value of the command.
      */
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        if (intent == null) return Service.START_NOT_STICKY
+        if (intent == null) return START_NOT_STICKY
 
         val uri = intent.getParcelableExtra<Uri>(BackupConst.EXTRA_URI)
 
@@ -179,7 +179,7 @@ class BackupRestoreService : Service() {
                 .subscribeOn(Schedulers.from(executor))
                 .subscribe()
 
-        return Service.START_NOT_STICKY
+        return START_NOT_STICKY
     }
 
     /**