Prevent FormsAppCompatActivity from loading fragments we don't use on restart

[hartez]

Description of Change

Prevent the FormsAppCompatActivity from attempting to restore fragments when being restored after being killed because of limited memory. Previously, the fragments were restored and then ignored by XF; in the case of nested fragments (e.g., a TabbedPage or MasterDetailPage containing another TabbedPage), this caused an IllegalStateException (followed by a crash) because a view could not be associated with the nested fragment. Now the FormsAppCompatActivity won't attempt to restore the fragments we weren't going to use anyway. (Bonus: slight memory improvement!)

Bugs Fixed

• 42075 – IllegalStateException - Fragment does not have a view

API Changes

None

Behavioral Changes

If a user is deliberately matching up and restoring fragments by tag when the application is restored, that user will have to derive from FormsAppCompatActivity and override the AllowFragmentRestore property to return true.

PR Checklist

• Has tests (if omitted, state reason in description)
• Rebased on top of master at time of PR
• Changes adhere to coding standard
• Consolidate commits as makes sense

… restart

[samhouts]

👍

[jassmith]

👍