goldfish-opengl: nuke isNoFlagsMemoryTypeIndexForGuest

According to the spec, all memory types should have flags
associated with them, and the no flags memory type may be
just of a consequence of looping to VK_MAX_MEMORY_TYPES,
rather than memoryTypeCount.

BUG=233803018
TEST=compile

Change-Id: I0eafb1364c5fbae025b5c44a8cb6ec7ca71ca155