[Media TTT] Update timeout to take accessibility settings into account.

This will extend the timeout for the chip to at least 10s if a11y is on,
or longer if the user has it set to longer.

Also update the default timeout to 4s to make it a bit longer.

Fixes: 229558433
Test: manual
Test: media.taptotransfer tests
Change-Id: I65110c83009c883b5107cf9eb3f46f4db3eba728