Merge mozilla-mobile#5853

5853: Closes mozilla-mobile#4466, mozilla-mobile#5278: Migration: Filter about:home tabs and rewrite about:reader URLs. r=grigoryk a=pocmo

For mozilla-mobile#4466 an mozilla-mobile#5278.

We are now:
- Skipping tabs that are pointing to `about:home` - Fenix can't handle that URL.
- Rewriting `about:reader` URLs to the original URL. Fenix can't handle `about:reader` URLs but can just load the original URL.

Co-authored-by: Sebastian Kaspari <[email protected]>

Issue mozilla-mobile#5818: Try to migrate default search engine.

Merge mozilla-mobile#5751

5751: update/subscribe push race workaround r=jonalmeida a=grigoryk



Co-authored-by: Grisha Kruglov <[email protected]>

Set version to 27.2.0.

Set version to 28.0.3.

Set version to 28.0.2.

Set version to 27.1.1.

Set version to 28.0.1.

Merge mozilla-mobile#5575

5575: Closes mozilla-mobile#5097: Add web domain for autofill in authentication dialog r=grigoryk a=rocketsroger



Co-authored-by: Roger Yang <[email protected]>

Set version to 27.1.0.