Make the full-screen dialog text editable in gallery (#13690)

This fixes https://github.com/dart-lang/sdk/issues/32598.

We are about to begin building gen_snapshot as a multi-arch binary,
which when run as x86_64 will generate arm64 AOT output, and when run as
i386 will generate armv7 AOT output.

Currently, gen_snapshot is an x86_64 binary, so this change is
effectively preventative in nature, and is a no-op with the current
snapshotter.

* Update text_style_test

* Update template .gitignore rules

* Remove old packages rule

* Remove IDE folders from gitignore templates

* Prefer ios.tmpl/.gitignore

* Update text_form_field.dart

* Update text_form_field_test.dart

* Update text_form_field_test.dart

* Update text_form_field_test.dart

* Bump mockito to 3.0.0-alpha+3

* Type annotation

Switch to the new Matrix4.tryInvert method to avoid throwing and catching (#15771) exceptions while performing hit testing.

Fixes https://github.com/flutter/flutter/issues/16332

* always schedule first frame when creating ticker, regardless of phase or frame

* Remove explicit child nodes

* Remove semantics on no-op menu buttons

* Add a dummy action to the overflow bar

Includes:
* Add armv7 support to create_ios_framework script (#4942)
* Roll Dart to version 09e1766e6caa537e1271fbce04ebcbf8212b6569 (#4941)

This renames the chip's border attribute to 'shape' so that it is consistent with the other places where we supply a ShapeBorder.

This is a breaking change, but a very small one: the border attribute was introduced only a few months ago, and is not widely used.

* Roll engine to version be070599a30413bd203f2d77d2179220c5569c08
(includes a roll of dart to version 3e6b8717fedce5cc28a21616f4591683c211f752

Fixes https://github.com/flutter/flutter/issues/16200

Includes:
* Revert "Roll dart to 4bcf8ad411bd90da16d44ad399bf350e8423eac9" (flutter/engine#4936)
* libtxt: render fake bold text if a bold font is not available (flutter/engine#4933)
* Set FlutterTexture copyPixelBuffer return nullable (flutter/engine#4934)
* Roll dart to 4bcf8ad411bd90da16d44ad399bf350e8423eac9 (flutter/engine#4929)

This reverts commit e9d1c8e4.

* Add disable Cupertino Switch example

* keep trailing commas consistent

* fix Cupertino Switch example linter error

Includes:
* libtxt: add missing dependency for Mac/iOS builds (flutter/engine#4931)
* libtxt: use Helvetica as a fallback font on iOS 8 and earlier (flutter/engine#4930)
* Make Rect.largest match the "largest" rect used in DefaultLayerBuilder (flutter/engine#4926)
* [vulkan] Add VK_ERROR_NOT_PERMITTED_EXT
* Roll buildroot to 8dddd90bf943a8174913564353b30a3b11ee0f7a (flutter/engine#4928)
* Set the asset bundle path when initializing the shell in the embedder API (flutter/engine#4925)

* re-enable verify-only failing test for out of sync deps and update deps to latest version