Update rustflags to work with new hal_v4 types

Bug: 369375199
Test: treehugger
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:4daa65d001fa74dfea32df06daf61171bee2c3dc)
Merged-In: I5ebea2568301d6bc61783f18829ae0fb386a7fc3
Change-Id: I5ebea2568301d6bc61783f18829ae0fb386a7fc3
1 file changed