Replace -Weverything with -Wextra

-Weverything is not recommended, use -Wextra.

Requires adding a few more disabled warnings to libvulkan,
-Weverything appears to not turn on warnings that were disabled
by earlier command line arguments, while -Wextra does.

Bug: 143713277
Test: m native
Change-Id: I3997c2afe094deca66018e3cc43921aaecd82028