[Media TTT] Align the timeout with heads up notifications.

This reduces the timeout to 5s by default, and 10s for "in progress"
actions like loading. The 5s timeout is the same as the heads up
notification timeout, since the UIs are in similar places doing similar
things.

Fixes: 271302820
Test: verify loading chip disappears after 5s
Test: verify success chip disappears after 10s
Test: atest MediaTttSenderCoordinatorTest
Change-Id: I6bf500c55102f2339cd112fc373ba85a88f93d61