Mojo: Send Android args in a string array, not JSON.

Mojo: Send Android args in a string array, not JSON.

Use adb shell am's comma-separated --esa argument.
(escape commas in the script and un-escape them in Java)

John was hitting a JSON parsing error/crash locally.
This should circumvent that error and reduce complexity.

BUG=NONE
TEST=Android Mojo and Mandoline still works as expected.
R=sky@chromium.org,jam@chromium.org

Committed: https://crrev.com/089ac0057f850ad3a26a6bd9f86d9043c461bdbd
Cr-Commit-Position: refs/heads/master@{#333018}

[msw, 2015-06-05 00:20:33]

Hey John and Scott, please take a look; thanks!

[msw, 2015-06-05 02:36:50]

(we could also apparently use JsonReader.setLenient(true) if we want a different
workaround... I don't know why the JSON is invalid...)

[jam, 2015-06-05 03:53:59]

lgtm

[msw, 2015-06-05 05:07:16]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2015-06-05 05:07:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1151363004/20001

[commit-bot: I haz the power, 2015-06-05 06:24:42]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-06-05 06:25:58]

Patchset 2 (id:??) landed as
https://crrev.com/089ac0057f850ad3a26a6bd9f86d9043c461bdbd
Cr-Commit-Position: refs/heads/master@{#333018}