Nested multi-level $lambda + $return.success bug

Looks like there's something wrong when there's more than one level of `trigger` + `$return.success` combo.

For example, this works fine until the `encoding_test` and `filter_test` calls but stops right before `sha256_test`.

```
{
"actions": {
"$load": {
"type": "$script.include",
"options": {
"items": [
{
"url": "https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"
},
{
"text": "var randomcolor = function() { return '#'+Math.floor(Math.random()*16777215).toString(16); }"
},
{
"url": "https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.9-1/crypto-js.min.js"
},
{
"url": "https://rawgit.com/mathiasbynens/he/master/he.js"
}
]
},
"success": {
"trigger": "encoding_test",
"options": {
"text": "brian's page"
},
"success": {
"trigger": "filter_test",
"success": {
"trigger": "sha256_test"
}
}
}
}
}
}
```

Start by reproducing the JSON example from the issue and tracing the nested trigger and $return.success flow, which currently stops before sha256_test. Identify the relevant Android/Java entry point and add coverage for multiple nested levels. Done means the example reaches sha256_test successfully.

Written by the indexing model from the issue text.