feat(BottomSheet): add suport dismissOnBackButton

src/bottomsheet/bottomsheet-common.ts

@@ -23,6 +23,7 @@ export interface BottomSheetOptions {
     animated?: boolean; // An optional parameter specifying whether to show the sheet view with animation.
     dismissOnBackgroundTap?: boolean; // An optional parameter specifying whether to dismiss the sheet when clicking on background.
     dismissOnDraggingDownSheet?: boolean; // An optional parameter specifying whether to disable dragging the sheet to dismiss.
+    dismissOnBackButton?: boolean; // An optional parameter that specifies whether to close the sheet when pressing the back button.
     closeCallback?: Function; //  A function that will be called when the view is closed. Any arguments provided when calling shownInBottomSheet.closeCallback will be available here.
     trackingScrollView?: string; // optional id of the scroll view to track
     transparent?: boolean; // optional parameter to make the bottomsheet transparent

src/bottomsheet/bottomsheet.android.ts

@@ -51,6 +51,10 @@ export class ViewWithBottomSheet extends ViewWithBottomSheetBase {
                     },
 
                     onBackPressed(dialog: com.nativescript.material.bottomsheet.BottomSheetDialog) {
+                        if(bottomSheetOptions.options && bottomSheetOptions.options.dismissOnBackButton === false){
+                            return true;
+                        }
+
                         if (!owner) {
                             return false;
                         }