m7-common: Remove modem links, generate firmware symlinks

* Because remounting the system partition to symlink firmware is dumb.

Change-Id: I55b0ad232fb5dbb1abc57bcb2ace66be1737e7ca

Conflicts:

	rootdir/Android.mk
m7-common: include more firmware images for symlinking

Change-Id: I499f6a25fc881d365324cde239b448b1faaf3b62
m7-common: split firmware linking by variant

Change-Id: Id110fc7a38efe78a16c946fea5750cc37b9ea9da
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