Added File Attachment sepolicy for betterbug
Bug: 237287659
Test: Attach files from local directory and confirm it can be attached.
Change-Id: I2e77894d4b12a302f0498aab3aa59be6fb95b795
Signed-off-by: George Lee <geolee@google.com>
(cherry picked from commit 27725bd144ba6a21dde6038f87358a0d74d81992)
Merged-In: I2e77894d4b12a302f0498aab3aa59be6fb95b795