infra: Increase gles1_conformance_tests timeout In anticipation of GLES1 ubershader updates that result in faster frame times, but more compiles. The GLES1 conformance tests iterate through every state and render one frame, which is slower when you link a new program for each. Bug: angleproject:6644 Change-Id: I70501ea38505428569ba518710ecb03ce198db18 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3292511 Commit-Queue: Cody Northrop <cnorthrop@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Lingfeng Yang <lfy@google.com>