composer: increase timeout for VTS

Some devices expose more then a few display configurations which
requires a longer timeout for the VTS to complete.

Bug: 180690432
Test: run vts VtsHalGraphicsComposerV2_4TargetTest
Change-Id: I4bef6354109d9244997c4b70e8c66b176ac90b10
(cherry picked from commit 5c9725db)