This reverts commit 4caa68b8.

* Identify text fields as such to a11y on Android

* Add focus flag

Fixes https://github.com/flutter/flutter/issues/12820

Fixes https://github.com/flutter/flutter/issues/12772

This fixes the Fuchsia build.

On hide keyboard, reset the bottom padding to the safe area inset on
devices running iOS 11 or higher.

This change exposes the view safe area insets (introduced in iOS 11) to
the framework via MediaQuery.of(context).padding. Safe area insets are
the view insets (padding) inside of which content can be relied on to
display without truncation/clipping, as would occur with e.g. the iPhone
X sensor notch.

As this API was added in iOS 11, we place it behind a runtime guard
checking OS level.

Until the runtime support for @avialable lands in the next Fuchsia
buildtools rev, ignore -Wunguarded-availability-new around the safe area
insets check and use an FML runtime check instead.

Refactor querying of supported Vulkan extensions.

* Android SeekBars announce their value

* style

Previously, these binaries were in /system/apps, which is going away. Also,
rename flutter_runner to flutter_jit_runner to match flutter_aot_runner.

Instead, the rasterizer can be accessed via the platform view.

* Fix regression - configure asset bundle

* Fix formatting

This will replace the one in the diagnostic server

* Only post UIAccessibilityLayoutChangedNotification if layout actually changed

* ++

* review comment

This reverts commit a48b5f6d.

Refactoring related to use of the embedder APIs on macOS
host builds.

* Read core platform kernel file during Dart initialization.

Currently service isolate is initialized from the source code parsed by VM.
This CL changes it so service isolate created during Dart initialization
is created from the kernel platform.dill file if it is present in the application
bundle. Then this platform kernel file is kept in dart_init module and reused
for application sciprt isolates.

* Reformat and merge

* Use accessor method

* Avoid passing running_from_kernel param. Add TODO for cleanup. Rename param.

* add luminance getter to color

* tests

* nit

This reverts the previous roll to 33397f which included an assertion we ended up tripping over on certain scenes. A Skia issue has been filed for this https://bugs.chromium.org/p/skia/issues/detail?id=7225.