Increase the valid name of the iface to IFNAMSIZ

Define MAX_IFACE_LENGTH as IFNAMSIZ instead of 10, to
prevent netd from treating an interface name 'rmnet_sdio0'
as invalid.
Also fix an off-by-one error.

bug:5675718
Change-Id: I2b6ba823c89941031e5898b24dab388cd9c2dae8
3 files changed