Revert "Don't reuse the browser for CrOS tests"
Revert "Don't reuse the browser for CrOS tests"

This reverts commit 88f2201b3d15cf6157323f7a62bd5144c08d8a71.

Reason for revert: Need to update a unit test

Original change's description:
> Don't reuse the browser for CrOS tests
>
> Bug: chromium:1296788
> Change-Id: I0f7b8adeeac73bbe4d82c7c17cd9db4eaec95f94
> Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/3561483
> Auto-Submit: Ryan Heise <50ee0a56d43e9e15503d071e9ceb1a6059353025@google.com>
> Reviewed-by: Eduardo Yap <eduardoyap@google.com>
> Commit-Queue: Eduardo Yap <eduardoyap@google.com>
> Commit-Queue: Ryan Heise <50ee0a56d43e9e15503d071e9ceb1a6059353025@google.com>

Bug: chromium:1296788
Change-Id: Ia628dd9d48e702cdb5c15c11543694f865a84a88
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/3562565
Auto-Submit: Ryan Heise <50ee0a56d43e9e15503d071e9ceb1a6059353025@google.com>
Reviewed-by: Ryan Heise <50ee0a56d43e9e15503d071e9ceb1a6059353025@google.com>
Commit-Queue: Rubber Stamper <d516c4cc2192058ab8dae3d306acbdaf2ce6574f@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <d516c4cc2192058ab8dae3d306acbdaf2ce6574f@appspot.gserviceaccount.com>

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