Use explicit TaskQueueFactory for FrameGeneratorCapturer in BitrateEstimatorTest.
Use explicit TaskQueueFactory for FrameGeneratorCapturer in BitrateEstimatorTest.

This replaces the implicit usage of GlobalTaskQueueFactory

Bug: webrtc:10284
Change-Id: Iebfcda2bd3ccf25c517c668e96e424e7665b13da
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/133578
Commit-Queue: Danil Chapovalov <55de8d9c2b5977da2dd48f967f21f9d606b172a5@webrtc.org>
Reviewed-by: Sebastian Jansson <c24d1bc144eb7c11e553f59153fa17dba85ca83e@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#27691}
ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc