FrameRateCtsActivity: increase frame rate switch grace period

A recent platform change (ag/11668114) was introduced to make sure
animations are done at high refresh rate. As a result, when the CTS
activity launches, the animation would cause the refresh rate to stay
at high for a longer time.

Bug: 155367075
Test: CtsGraphicsTestCases
Change-Id: I04e497215879c7bbfc363a7e5f0dcfe6d7c7179b
1 file changed