2.x: Fix subscribeWith documentation examples (ReactiveX#5647)

Author: dimsuz

src/main/java/io/reactivex/Completable.java

@@ -1686,11 +1686,11 @@ public final void subscribe(CompletableObserver s) {
      * Completable source = Completable.complete().delay(1, TimeUnit.SECONDS);
      * CompositeDisposable composite = new CompositeDisposable();
      *
-     * class ResourceCompletableObserver implements CompletableObserver, Disposable {
+     * DisposableCompletableObserver ds = new DisposableCompletableObserver() {
      *     // ...
-     * }
+     * };
      *
-     * composite.add(source.subscribeWith(new ResourceCompletableObserver()));
+     * composite.add(source.subscribeWith(ds));
      * </code></pre>
      * <dl>
      *  <dt><b>Scheduler:</b></dt>

src/main/java/io/reactivex/Maybe.java

@@ -3772,11 +3772,11 @@ public final Maybe<T> subscribeOn(Scheduler scheduler) {
      * Maybe&lt;Integer&gt; source = Maybe.just(1);
      * CompositeDisposable composite = new CompositeDisposable();
      *
-     * MaybeObserver&lt;Integer&gt; ms = new MaybeObserver&lt;&gt;() {
+     * DisposableMaybeObserver&lt;Integer&gt; ds = new DisposableMaybeObserver&lt;&gt;() {
      *     // ...
      * };
      *
-     * composite.add(source.subscribeWith(ms));
+     * composite.add(source.subscribeWith(ds));
      * </code></pre>
      * <dl>
      *  <dt><b>Scheduler:</b></dt>

src/main/java/io/reactivex/Observable.java

@@ -10939,11 +10939,11 @@ public final void subscribe(Observer<? super T> observer) {
      * Observable&lt;Integer&gt; source = Observable.range(1, 10);
      * CompositeDisposable composite = new CompositeDisposable();
      *
-     * ResourceObserver&lt;Integer&gt; rs = new ResourceObserver&lt;&gt;() {
+     * DisposableObserver&lt;Integer&gt; ds = new DisposableObserver&lt;&gt;() {
      *     // ...
      * };
      *
-     * composite.add(source.subscribeWith(rs));
+     * composite.add(source.subscribeWith(ds));
      * </code></pre>
      * <dl>
      *  <dt><b>Scheduler:</b></dt>

src/main/java/io/reactivex/Single.java

@@ -2801,11 +2801,11 @@ public final void subscribe(SingleObserver<? super T> subscriber) {
      * Single&lt;Integer&gt; source = Single.just(1);
      * CompositeDisposable composite = new CompositeDisposable();
      *
-     * class ResourceSingleObserver implements SingleObserver&lt;Integer&gt;, Disposable {
+     * DisposableSingleObserver&lt;Integer&gt; ds = new DisposableSingleObserver&lt;&gt;() {
      *     // ...
-     * }
+     * };
      *
-     * composite.add(source.subscribeWith(new ResourceSingleObserver()));
+     * composite.add(source.subscribeWith(ds));
      * </code></pre>
      * <dl>
      *  <dt><b>Scheduler:</b></dt>