8230 Remove jsoncpp from desktop Linux shell setup (cla: yes)

8231 Removed Activity reference from AccessibilityBridge by using a View for insets instead of the Activity (cla: yes)

8233 Enable Linux shell build (cla: yes)

8234 Use the GPU thread for Android surface on-screen context lifecycle operations (cla: yes)

8237 Mirror Android platform views a11y tree in the Flutter a11y tree. (cla: yes)

8241 fix video player dismiss when there is a iOS platform view (cla: yes)

8246 Remove more forced crashes from FlutterJNI (cla: yes)

8247 Fix incorrect vertices colors length check (cla: yes)

8249 Allow specifying an alternate Mac host SDK. (cla: yes)