Merge changes from topic "remove-fde"

* changes:
  Remove unused FDE methods from StorageManager
  Stub out some FDE methods in StorageManager
  Stop trying to update FDE password from LockSettingsService
  Remove clearEncryptionPassword() from LockPatternUtils
  Stop trying to get/set fields in FDE footer
  Stop checking FDE password cache
  Remove checks for FDE in 'adb backup'