[Android MR] Postpone route selection until session launch

Previously, we unselect and re-select the route due to CAF limitation.
The reason is that we need to set the receiver app ID after the user
choose a device. However CAF won't be able to know a device was selected
after the receiver app ID gets changed.

In this CL, to solve the issue, we intercept the click event in
MediaRouteChooserDialog (which would select the route automatically).
The route selection is postponed right before session launch. Therefore
we are able to set the receiver app ID and select the route to get rid
of CAF limitation.

Bug: 711860
Change-Id: I5b1534d36d540b62199a6fb739c56ad5131c2711
Reviewed-on: https://chromium-review.googlesource.com/c/1351893
Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Commit-Queue: Zhiqiang Zhang <zqzhang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611437}
4 files changed