Don't rely on transitively included headers

One must explicitly include what it need.
time.h for clock_gettime
float.h for FLT_MAX
string.h for memset

Bug: 37629934
Test: build

Merged-In: I1030a9c9ff3c2de4c5febabc3064d6976e9535cf
Change-Id: I5a8fd84a10aeeab2258f78a0ac992de0afa33d00
3 files changed