Add Vulkan dEQP level feature flag

This change adds a feature flag that specifies the date associated
with the Vulkan dEQP tests that a device claims to pass.

Bug: 136573508

Change-Id: I0cec29fe5f69f228faaa2298b7f5b65bcf988dba
Merged-In: I0cec29fe5f69f228faaa2298b7f5b65bcf988dba