Fix bubble overflow position after rotating on larger screen

The code was passing the index of the bubble rather than the
actual position onscreen so the resulting translation was incorrect.

Test: manual - be on a large screen / tablet
             - expand bubbles, select the overflow
             - rotate the device
             => observe that the overflow container remains with
                the rest of the bubbles and doesn't jump around
Bug: 223911182
Change-Id: I95403f57e40e8c428ea9694e6fb93b0b0478c530