DownloadFile Unhandled Promise Rejection

Dependencies:
```
"react-native": "0.61.2",
"react-native-fs": "^2.14.1"
```

Node version: `10.15.3`

I am using the `downloadFile` function as such:
```
const result: {
jobId: number;
promise: Promise;
} = await RNFS.downloadFile({
toFile,
headers: {
Accept: 'application/pdf',
},
background: true,
cacheable: true,
discretionary: true,
connectionTimeout: 120,
progressDivider,
progress: this.onDownloadProgress,
}).promise
```

within a React component. When I fire this function, I *sometimes* immediately receive the following error in the metro bundler output logger (new feature of RN v0.61.2)

```
Possible Unhandled Promise Rejection (id: 0):
TypeError: null is not an object (evaluating 'segments[key].toString')
logException@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:119853:30
logError@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:136781:54
_callee10$
tryCatch@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:25733:23
invoke@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:25908:32
tryCatch@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:25733:23
invoke@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:25809:30
http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:25821:21
tryCallOne@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:27088:16
http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:27189:27
_callTimer@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:30643:17
_callImmediatesPass@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:30679:19
callImmediates@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:30898:33
callImmediates@[native code]
__callImmediates@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:2695:35
http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:2472:34
__guard@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:2678:15
flushedQueue@http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false:2471:21
flushedQueue@[native code]
invokeCallbackAndReturnFlushedQueue@[native code]
```

`segments[key]` is null somewhere, and there is no reference to `segments` anywhere in my project. Any thoughts on what the underlying issue could be? Help is much appreciated.