Picks up changes to include inlined frames and line numbers in AOT stack traces.

Fixes https://github.com/flutter/flutter/issues/7579

In a previous change I re-included the observatory assets in the Fuchsia build, but didn't notice this bit here.

After this, if Settings::enable_observatory can be set to true somehow, the Observatory will come up in Flutter apps on Fuchsia. Unfortunately, I'm not sure how to do that.

* Document the need to sync the engine repo to avoid #8005

* Flit gclient sync and git pull

See https://github.com/flutter/flutter/issues/6807

Ensure that the text input keyboard is reloaded if the view keyboardType
changes.

Fixes https://github.com/flutter/flutter/issues/7724

Added:
* UIRequiredDeviceCapabilities=[arm64]
* MinimumOSVersion=8.0

Fixes https://github.com/flutter/flutter/issues/7723

Provide a default status bar tap handler for FlutterAppDelegate.
By default, taps are passed to the key window's rootViewController if
it's a FlutterViewController. Apps with custom app delegates can
customize this behaviour to send the tap to the FlutterViewController(s)
they prefer by overriding touchesBegan:withEvent.

* [iOS] Ensure FlutterMain is called before interacting with the engine in any way.

* Licenses

The PlatformView superclass constructor was posting a task to the UI thread
that adds the view to the shell's global list.  This could result in UI thread
operations seeing PlatformView instances that are not fully constructed and do
not yet have an engine.

This was happening in https://github.com/flutter/flutter/issues/7735

On iOS, when a tap is detected in the status bar, provide a means to
pass that touch event through to one or more FlutterViewControllers to
trigger a scroll to top. In iOS apps, scroll to top should occur under
the following conditions:

1. There is one and only one UIScrollView visible with
   scrollsToTop == YES.
2. The status-bar is in standard height mode, not in double-height mode.
   In double-height mode, the expected behaviour is to trigger a switch
   to the application associated with the double-height status bar.
3. A tap or a drag gesture occurs that is entirely constrained to the
   status bar frame. (We currently only handle the tap scenario).

Unfortunately, AppDelegates only get touchesBegan events for status bar
taps, though get get touchesBegan and touchesEnded events for drags
within the status bar frame. As such, we currently synthesise the
touchesEnded event for taps.

The Dart tests were migrated from the flutter/test/engine suite in the
framework repository

This is intended to match the exit codes returned by the Dart command line tool