Mark webgl2_conformance_test as flaky on Pixel 2

conformance2/transform_feedback/switching-objects.html is flaky

Bug: 1022410
Change-Id: Id7e28e5c82affda12612bbcd64f8d9e0c2da308a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1903612
Auto-Submit: kylechar <kylechar@chromium.org>
Commit-Queue: Brandon Jones <bajones@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713504}

content/test/gpu/gpu_tests/test_expectations/webgl2_conformance_expectations.txt

@@ -712,6 +712,7 @@ crbug.com/1008535 [ android qualcomm-adreno-(tm)-540 passthrough ] conformance2/
 crbug.com/906735 [ android qualcomm ] conformance2/textures/video/tex-2d-rgba8ui-rgba_integer-unsigned_byte.html [ Failure ]
 crbug.com/981216 [ android qualcomm-adreno-(tm)-540 ] deqp/functional/gles3/fbocolorbuffer/tex2d_01.html [ RetryOnFailure ]
 crbug.com/949321 [ android qualcomm ] deqp/functional/gles3/framebufferblit/default_framebuffer_02.html [ RetryOnFailure ]
+crbug.com/1022410 [ android qualcomm ] conformance2/transform_feedback/switching-objects.html [ RetryOnFailure ]
 
 # This test is failing on Android Pixel 2 and 3 (Qualcomm)
 # Seems to be an OpenGL ES bug.