[Android] Catch device exceptions from individual test shards.

[Android] Catch device exceptions from individual test shards.

Currently, if any one device fails but all tests pass on other devices,
the test run fails _even though_ all tests have succeeded. This patch
changes that -- if all tests pass, the test run will pass even if a
device fails. (If a test fails, or if all devices fail and not all tests
run, the test run will still fail.)

BUG=

Committed: https://crrev.com/1ca6eaede71ea9ac9f00a0c3bb55119c8ddf676e
Cr-Commit-Position: refs/heads/master@{#340876}

[jbudorick, 2015-07-29 05:43:39]

jbudorick@chromium.org changed reviewers:
+ mikecase@chromium.org, perezju@chromium.org

[perezju, 2015-07-29 08:50:17]

lgtm

[jbudorick, 2015-07-29 13:01:26]

The CQ bit was checked by jbudorick@chromium.org

[commit-bot: I haz the power, 2015-07-29 13:01:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1262103002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1262103002/1

[commit-bot: I haz the power, 2015-07-29 13:15:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-29 13:16:16]

Patchset 1 (id:??) landed as
https://crrev.com/1ca6eaede71ea9ac9f00a0c3bb55119c8ddf676e
Cr-Commit-Position: refs/heads/master@{#340876}