Turn off relaxed-template-template-args as a workaround

ToT switched on "relaxed-template-template-args" by default. This does
not work with our outdated libc++. Turn it off until we have the new
libc++.

Test: build with Kokoro ToT Clang (build 2417)
Bug: 341084395
Bug: 332594828
Change-Id: I994c476c1f7b4abd81e5ae0bde4e1f9afd1aa920