m4: correct Voice Speaker to fix in-call speakerphone

Change-Id: I98a6f23918a40fa5f406df64b8c6e307fbb07ef6
m4: add a FUSE service for OTG storage
m4: fix OTG mountpoint permissions
m4: store encryption keys in the "extra" partition
m4: don't mount anything in /data

Otherwise, encryption will fail to unmount it cleanly. Inspired by what
m7 does.
m4: dm-crypt is built-in these days
m4: no need to manually start qcamerasvr
m4: drop a bunch of nonexistent stuff from init
m4: remove unused wpa_supplicant config file
m4: add user and group info for wpa_supplicant