Changed minimum value of rx2.buffer-size to 1

[hvesalai]

Before the minimum value you could set with the system variable rx2.buffer-size was 16. With this commit, that is changed to 1.

[codecov]

Codecov Report

Merging #5391 into 2.x will increase coverage by 0.01%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##               2.x    #5391      +/-   ##
===========================================
+ Coverage     96.1%   96.12%   +0.01%     
+ Complexity    5781     5779       -2     
===========================================
  Files          630      630              
  Lines        41195    41195              
  Branches      5726     5726              
===========================================
+ Hits         39591    39599       +8     
+ Misses         632      624       -8     
  Partials       972      972

Impacted Files	Coverage Δ	Complexity Δ
src/main/java/io/reactivex/Flowable.java	100% <100%> (ø)	521 <1> (ø)	⬇️
...vex/internal/operators/single/SingleTakeUntil.java	86.88% <0%> (-8.2%)	2% <0%> (ø)
...al/operators/observable/ObservableSampleTimed.java	93.33% <0%> (-5%)	3% <0%> (ø)
...nternal/operators/parallel/ParallelSortedJoin.java	90.57% <0%> (-4.35%)	2% <0%> (ø)
...reactivex/internal/operators/single/SingleAmb.java	96.36% <0%> (-3.64%)	9% <0%> (-1%)
...activex/internal/operators/single/SingleCache.java	97.05% <0%> (-2.95%)	23% <0%> (-1%)
.../internal/operators/flowable/FlowableInterval.java	94.44% <0%> (-2.78%)	3% <0%> (ø)
...ava/io/reactivex/internal/util/HalfSerializer.java	97.5% <0%> (-2.5%)	22% <0%> (-1%)
...ernal/operators/flowable/FlowableFromIterable.java	93.04% <0%> (-2.14%)	5% <0%> (ø)
...nternal/operators/observable/ObservableWindow.java	98% <0%> (-2%)	3% <0%> (ø)
... and 36 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 2fa773c...1cbad74. Read the comment docs.