Merge the 2019-01-01 SPL branch from AOSP-Partner

* security-aosp-nyc-mr2-release:
  AOSP/Email - Second part of the Security Vulnerability fix -   Email App: Malicious app is able to compose message with hidden   attachments and bypass attachments path checks attaching private files   from /data/data/com.android.email/*

Change-Id: Ief952cec19ee7fd07d89da363d80ad2c414989e7