MB: Fix incorrect iOS builder names.
MB: Fix incorrect iOS builder names.

In https://codereview.webrtc.org/2239643002/ MB was turned on
for the iOS GYP bots. This exposed an incorrect config for the
iOS simulator bots in client.webrtc.

BUG=589510
NOTRY=True

Review-Url: https://codereview.webrtc.org/2245393003
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#13778}

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