Prevent exfiltration of system files via user image settings.

This adds mitigations to prevent system files being exfiltrated
via the settings content provider when a content URI is provided
as a chosen user image.

The mitigations are:

1) Copy the image to a new URI rather than the existing takePictureUri
prior to cropping.

2) Only allow a system handler to respond to the CROP intent.

A similar change is made in ag/17003629 which uses the same
mechanism.

Bug: 187702830
Test: builds
Change-Id: Iba9e08b3cf9e31c162354f09aaf6b4f9afb6bd27
(cherry picked from commit fac28abbe64a1c3e430414f35139988ef96edb7c)
Merged-In: Iba9e08b3cf9e31c162354f09aaf6b4f9afb6bd27
1 file changed