Our minimum build version listed on source.android.com is 10.10. Change
the minimum used SDK to 10.10, but keep the deployed version at 10.8 so
that our distributed tools still work on older versions.
CoreBluetooth/CoreBluetooth.h isn't available directly in older SDKs,
but we need to include it in the 10.12 SDK.
Test: `m -j` with 10.11, 10.12 SDKs.
Test: Verified the builders all have at least 10.10 sdk available.
Change-Id: I82321875b8b3a4099ea829ce2d75e1af29cb38c6