Add is_temp field to iOS schema fragment.

This adds an is_temp field to the wikipedia_ios_app fragment, and bumps the fragment version in the relevant schemas that make use of the fragment.

• This also fixes an issue with the ios_talk_page_interaction schema, which had incorrect indentation in one of its description fields. To fix this properly, and to make future updates pass tests, all the previous versions of this schema have been updated too, which should not result in any functional changes.

Bug: T374058