Fix cursor position after delete gesture

Deleting text inside a selection causes the selection to be updated
asynchronously, so setting the cursor position synchronously after the
deletion could get overwritten by the asynchronous update.

This is fixed by setting the cursor position before deleting the text.

Bug: 266984004
Test: tested manually
Change-Id: I8801cc0bc9d0a3acd7952e2a88691f480c58d453