SDL-0274: add preferred FPS to VideoStreamingCapability

[shiniwat]

Fixes #3243

This PR is ready for review.

Risk

This PR makes no API changes.

Testing Plan

N/A

Summary

This PR is for SDL-0274: add preferred FPS to VideoStreamingCapability.

Changelog

Breaking Changes

• N/A

Enhancements

• N/A

Bug Fixes

• This takes care of sdl_core issue [SDL 0274] Add preferred FPS to VideoStreamingCapability #3243.
  Please note that rpc_spec submodule must be updated. I will update the submodule as soon as another PR at [SDL 0274] add preferred FPS to VideoStreamingCapability rpc_spec#229 has been merged.

Tasks Remaining:

• none

CLA

• I have signed the CLA

[jordynmackool]

Hi @shiniwat, this PR should point to the branch of the RPC Spec that contains the changes needed for this feature.

RPC Spec changes are not merged until the feature has been properly tested with all the required projects and it is confirmed the feature will make it into the slated releases.

Once this PR is updated and tested against the RPC Spec feature branch, please tag me requesting a review.

[jordynmackool]

@shiniwat is this ready for Livio review?

[shiniwat]

Hi @jordynmackool,
While Travis CI seems to fail with "The job exceeded the maximum time limit for jobs, and has been terminated." error, the build works fine on my devbox (Ubuntu 1804). I believe this is ready for Livio review.

[jacobkeeler]

See comments

[jacobkeeler]

@shiniwat Please update the rpc_spec submodule to the latest develop to fix merge conflicts