[3/3]Settings: add "Accept all files" option...

…for incoming files via Bluetooth

 Vanilla Android requires the incoming file from Bluetooth to be
certain mime-types.
  The mime-types allowed are defined in
packages/apps/Bluetooth/src/com/android/bluetooth/opp/Constants.java
  But sometimes we need to accept files that is not in the list,such as
RAR archives
or APK packages.
  This patch makes "Accept all files" an option in Settings ->
Bluetooth -> (Menu),
and then saves users' choice to Settings Provider database.
  This will meet users' demand as well as keep the phone from unsafe
files
when users don't need to accept the files out of the mime-type
whitelist.

Change-Id: I5f04d3ccb45bd5c6525b746855bd19ccc8501d32