[BottomSheetBehavior] Allow avoiding STATE_HALF_EXPANDED

Is your feature request related to a problem? Please describe.
By popular request - https://stackoverflow.com/questions/59487982/android-how-to-disable-state-half-expanded-state-of-a-bottom-sheet:

• have behavior_fitToContents = false to try getting the view to have 2 possible states: expanded and collapsed with app defined fixed dimensions.
• a third - STATE_HALF_EXPANDED state and view height is introduced that's of no use.

Describe the solution you'd like
A behavior_skipHalfExpanded property/method that would have the behavior never set STATE_HALF_EXPANDED.

We also happily accept pull requests.

Inizia individuando BottomSheetBehavior e la gestione esistente degli stati fit-to-contents e half-expanded, quindi esamina i test correlati. Definisci il comportamento di skip in modo che fitToContents=false supporti solo gli stati expanded e collapsed, quindi verifica le transizioni di stato e la proprietà o il metodo pubblico nella suite di test.