Expose async writes to HTTP Stream Manager

[azkrishpy]

Issue #, if available:

Description of changes:

• Bind out the write data API #981 exposes write data to connections but stream manager's acquire API automatically calls connections with no boolean for useManualDataWrites. This change adds an overloaded implementation of acquire stream to add the manual writes as a boolean.
• This also changes native write data to avoid a copy by setting up a new global reference to user's byte array that will get cleaned up after callback is invoked or if the API errors out.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[TingDaoK]

let's add a test for this, if we don't already have one.
invoke the write data API with a local variable (Or somehow remove the reference to the object from java side). We should sill keep the data alive and works as expected since we keep the object referenced in C here.

[azkrishpy]

modified the existing happy path tests to create weak references and remove object, forced a gc and checked for the the weak reference to not be null.