RowTappedCommand executed only when selection changed

[tkouba]

Describe the bug
RowTappedCommand executed only in OnSelectionChanged method. When Row is already selected, RowTappedCommand is not executed.

To Reproduce
Steps to reproduce the behavior:

1. Create DataGrid with SelectionMode="Single"
2. Click on the Row
3. Click on the same Row again
4. RowTappedCommand is not executed

Expected behavior
RowTappedCommand executed on every row tap.

Desktop (please complete the following information):

• OS: Windows, Android (other platforms not tested)