[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=

Review URL: https://codereview.chromium.org/1262103002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#340876}

CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend