Remove EXTRA_KEY_TYPE intent data

This intent data was only used by CryptKeeperSettings, which has been
removed.  This is also one of the only remaining users of the
StorageManager.CRYPT_TYPE_* constants which were only ever intended to
be used with vold's Full Disk Encryption APIs, which have been removed.

Bug: 208476087
Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.password
      (No regressions seen; 2 tests fail both before and after.)
Change-Id: Id6e2c0f5ecc79f7372b29393e66ffbd66d52d7a2