Removed semantics elevation and thickness

Both elevation and thickness semantics properties and their related APIs were removed.

Both elevation and thickness semantics properties were created for Fuchsia's 3D rendering. They were never implemented and thus remained unused. There was also no other known usage for these properties. These properties added unnecessary code complexity and have been removed.

The following properties are removed SemanticsConfiguration.elevation, SemanticsConfiguration.thickness, SemanticsNode.thickness, SemanticsNode.elevation, and SemanticsNode.elevationAdjustment.

If you previously assigned these properties, remove the assignments.

Code before migration:

void describeSemanticsConfiguration(SemanticsConfiguration config) {
  config.label = 'my label';
  config.elevation = 1;
  config.thickness = 1;
}

Code after migration:

void describeSemanticsConfiguration(SemanticsConfiguration config) {
  config.label = 'my label';
}

Landed in version: Not yet
In stable release: Not yet

API documentation:

• SemanticsConfiguration
• SemanticsNode

Relevant issue:

• Issue 166092

Relevant PR:

• PR 168703