Ensure openInputStream cannot kill calling process

[herriojr]

This addresses issue #2339

ContentResolver.openInputStream falls back to using a stable content provider which will kill the main process if it fails. Never trust an external process as there may be many things that might cause this such as reinstalls, application updates, etc. Fall back to a FileNotFoundException.

[nathanmeade]

@herriojr I believe you need to add a reviewer such as @jrodbx to have this reviewed and merged

[herriojr]

@nathanmeade Apparently I don't have enough privs to do so? I can't modify the reviewers here like I can with other projects I work on.

[nathanmeade]

@herriojr I looked around for the contributing guidelines and I found this:

Contributing
If you would like to contribute code you can do so through GitHub by forking the repository and sending a pull request.

When submitting code, please make every effort to follow existing conventions and style in order to keep the code as readable as possible. Please also make sure your code compiles by running mvn clean verify.

Before your code can be accepted into the project you must also sign the [Individual Contributor License Agreement (CLA)](http://squ.re/sign-the-cla).

(from: https://square.github.io/picasso/)

After all of the above is squared away my best guess would be to try to ping the most recent reviewers of the PRs (jrodbx, afollestad,...)

[herriojr]

@nathanmeade all that was completed before I bother with the pull request.

[herriojr]

@jrodbx any input on this?