audio. Changes to SLES source creation.

Move creation of source smart pointer from engine to a static factory method in SLES source.
audio. Add log stream operator required for instrumentation.

Add std vector log stream operator.
Add SLES engine log stream operator.
Add SLES sink log stream operator.
audio. Audio resource loading changes.

Fixes to decode resource:
Translate read sampling rate to an SLES sampling rate constant.
Fix to how data is copied from load buffer to resource data memory buffer.
Copy last chunk of data at play end.

Changes to audio SLES buffer:
Add a shared pointer type to SLES buffer.
Add a factory method to create shared pointer to audio SLES buffer.

Changes to SLES source:
Change source initialization to use the buffer PCM format as the source format.