Fix PreferencesActivity crash on API < 17

[mueller-ma]

Signed-off-by: mueller-ma mueller-ma@users.noreply.github.com

[maniac103]

I wonder whether simply calling just isFinishing() wouldn't be sufficient here?

[mueller-ma]

Good question. Since I cannot reproduce this crash, I've looked up on the Internet and found this fix.

[maniac103]

Probably could/should check FragmentManager.isStateSaved() instead, and move the check into the respective case statement.

[mueller-ma]

FragmentManager.isStateSaved() isn't available on all API levels we support. This would require us changing the whole PreferenceActivity to use the AppCompat version of PreferenceFragment.

[maniac103]

Wouldn't that be a good either either way anyway? ;-)

[mueller-ma]

Definitely, but that's a larger task and I want to focus on the pending PRs and #257 for now. It's tracked in #1295.
I removed the isDestroyed() call.