3.x: remove no-arg dematerialize(); remove replay(Scheduler) variants

[akarnokd]

This PR removes some obsolete API.

The Flowable.dematerialize() and Observable.dematerialize() were inherently type-unsafe and have been removed. In Rx.NET, the extension methods allowed dematerialize() to be applied to Observable<Notification<T>> only, but there is no way for doing it in Java as it has no extension methods and one can't restrict a method to appear only with a certain type argument scheme.

Thereplay(Scheduler) and other overloads were carried over from the original Rx.NET API set but I can't rememeber if they had any use in the field. Most use cases capture the connectable anyway so there is no much benefit from inlining an observeOn into a connectable:

ConnectableFlowable<Integer> connectable = source.replay(); Flowable<Integr> flowable = connectable.observeOn(Schedulers.io()); // hand flowable to consumers flowable.subscribe(); connectable.connect();

[codecov]

Codecov Report

Merging #6539 into 3.x will decrease coverage by 0.11%.
The diff coverage is n/a.

@@ Coverage Diff @@ ## 3.x #6539 +/- ## ============================================ - Coverage 98.27% 98.16% -0.12%  + Complexity 6214 6198 -16  ============================================ Files 682 682 Lines 45505 45459 -46 Branches 6288 6288 ============================================ - Hits 44721 44625 -96  - Misses 243 276 +33  - Partials 541 558 +17

Impacted Files	Coverage Δ	Complexity Δ
src/main/java/io/reactivex/Flowable.java	100% <ø> (ø)	570 <0> (-5)	⬇️
...nal/operators/flowable/FlowableInternalHelper.java	100% <ø> (ø)	14 <0> (-1)	⬇️
src/main/java/io/reactivex/Observable.java	100% <ø> (ø)	545 <0> (-5)	⬇️
...ex/internal/operators/flowable/FlowableReplay.java	91.97% <ø> (-2.5%)	19 <0> (-1)
...nternal/operators/observable/ObservableReplay.java	95.76% <ø> (-2.13%)	19 <0> (-1)
...operators/observable/ObservableInternalHelper.java	100% <ø> (ø)	14 <0> (-1)	⬇️
...ernal/operators/flowable/FlowableFlatMapMaybe.java	90.82% <0%> (-4.84%)	2% <0%> (ø)
...a/io/reactivex/internal/util/QueueDrainHelper.java	95.83% <0%> (-4.17%)	55% <0%> (-3%)
.../operators/observable/ObservableFlatMapSingle.java	88.8% <0%> (-2.99%)	2% <0%> (ø)
...rnal/operators/observable/ObservableSwitchMap.java	93.61% <0%> (-2.66%)	3% <0%> (ø)
... and 22 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9e9d31c...9ee0786. Read the comment docs.