Make test target unsigned so that it compiles on chromium.
Make test target unsigned so that it compiles on chromium.

gfe-relnote: n/a test code only.
PiperOrigin-RevId: 244177964
Change-Id: I31bd5cbded223d950f14bda04cf09f402d97deea

google/quiche,google/quiche,google/quiche,google/quiche