Revert "[Android MR] Postpone route selection until session launch"

This reverts commit 7c453583f0c622cf928bb5d628ae9def8f03279f.

Reason for revert: This introduces some regression in some cases. The old logic works just fine so it is safe to revert.

Original change's description:
> [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}

TBR=zqzhang@chromium.org,tguilbert@chromium.org

Change-Id: I30322daecf8c866fdda9e846d0cb37d9a319f033
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 711860
Reviewed-on: https://chromium-review.googlesource.com/c/1352973
Reviewed-by: Zhiqiang Zhang <zqzhang@chromium.org>
Commit-Queue: Zhiqiang Zhang <zqzhang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611572}
4 files changed