Merge the 2019-10-05 SPL branch from AOSP-Partner

* security-aosp-nyc-mr2-release:
  AOSP/Email - Create an empty Bundle if originalExtras doesn't exit. Backporting the fix to fix NullPointerException.
  AOSP/Email - bug fix: do not allow composing message with hidden private data attachments.

Change-Id: I08483c349a84bdfa5d26e5ae80eb5d27480a534c