Fix tools_unittests in GN.
Fix tools_unittests in GN.

tools_unittests were failing when generated by GN and running on a device.

BUG=webrtc:5949
NOTRY=True

Review-Url: https://codereview.webrtc.org/2233843002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#13714}

TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc