Export to HTTP receiver at port 55681 for JS instead of default

[NathanielRN]

Description

We found through a breaking build that the JS SDK was failing to send traces:

2021-07-07T04:45:05.033Z	94f1dfb8-8122-4f68-a103-ed1ea7f0d30e	DEBUG	Instrumentation suppressed, returning Noop Span
2021-07-07T04:45:05.034Z	94f1dfb8-8122-4f68-a103-ed1ea7f0d30e	DEBUG	@opentelemetry/instrumentation-http %s instrumentation outgoingRequest http
2021-07-07T04:45:05.034Z	94f1dfb8-8122-4f68-a103-ed1ea7f0d30e	DEBUG	@opentelemetry/instrumentation-http http.ClientRequest return request
2021-07-07T04:45:05.053Z	94f1dfb8-8122-4f68-a103-ed1ea7f0d30e	ERROR	{"stack":"Error: Parse Error: Expected HTTP/\n    at Socket.socketOnData (_http_client.js:515:22)\n    at Socket.emit (events.js:376:20)\n    at Socket.emit (domain.js:470:12)\n    at addChunk (internal/streams/readable.js:309:12)\n    at readableAddChunk (internal/streams/readable.js:284:9)\n    at Socket.Readable.push (internal/streams/readable.js:223:10)\n    at TCP.onStreamRead (internal/stream_base_commons.js:188:23)\n    at TCP.callbackTrampoline (internal/async_hooks.js:134:14)","message":"Parse Error: Expected HTTP/","code":"HPE_INVALID_CONSTANT","reason":"Expected HTTP/","rawPacket":"\u0000\u0000\u0006\u0004\u0000\u0000\u0000\u0000\u0000\u0000\u0005\u0000\u0000@\u0000","name":"Error"}
END RequestId: 94f1dfb8-8122-4f68-a103-ed1ea7f0d30e
REPORT RequestId: 94f1dfb8-8122-4f68-a103-ed1ea7f0d30e	Duration: 1282.39 ms	Billed Duration: 1283 ms	Memory Size: 384 MB	Max Memory Used: 154 MB	Init Duration: 1519.08 ms	

Normally a collector will receive HTTP traces on port 55681. But in this PR the default port for HTTP was changed from 55681 to 4317. https://github.com/open-telemetry/opentelemetry-js/pull/2117/files#diff-c2d3229d30d1e2c1c6a140fad0ca1d9762f10481192b77143650057071eaead8L27

Here we set the environment variable for now to avoid confusion.

[NathanielRN]

This variable has a typo which was fixed: 3f5d7b8

[NathanielRN]

Filed issue to fix this upstream, hopefully this will make it into the next opentelemetry-js release! open-telemetry/opentelemetry-js#2331