m7-common: Move post-boot functionality into init

Change-Id: Ic089092b20708f0004076f7c86a92b37baaa296f
Fix USB tether

Change-Id: I10b19d4fb86fe477655af369726bc26ba301c0f4
m7-common: commonize some BoardConfig defines

Change-Id: I1641f8766d66d20905d29f6cd1e1a694916c83b1
m7-common: update mms overlays

frameworks/base - default config.xml:
- Remove content disposition override which should be limited to Sprint.

mcc311/mnc480:
- Remove overlays which duplicate the default configuration.
- Remove overrides for defaultMMSMessagesPerThread and
  defaultSMSMessagesPerThread.

mcc310mnc120:
- Remove overlays which duplicate the default configuration.
- Remove overrides for defaultMMSMessagesPerThread and
  defaultSMSMessagesPerThread.
- Remove enableSprintVVM which seems to no longer be used.

Change-Id: I6d8f089856c377b40752019f751cbd5cd64344d3
m7-common: Remove deprecated bnep services

Change-Id: I43e305b2d82b7c699a7207ede084037cf5f7a5f1
m7-common: overlay vzw-specific eri.xml

The mcc/mnc specific config.xml in values-xxx and xml-xxx were
apparently copied from Sprint. I see no reason they sould have been
included in the first place. This is re-affirmed by decompiling the
frameworks apks from stock.

Include more mcc/mnc eri overlays to correct the R(oaming) symbol in 3G.

Change-Id: I2b279cb03c28b7c2a580440a7456dee113338d3c