50369 Revert “Update minimum version to Xcode 11.0” (cla: yes, tool)

50370 Fall back to global cache and platform if null when injected into constructor (a: existing-apps, cla: yes, platform-ios, team, tool)

50371 Update minimum version to Xcode 11.0 (cla: yes, tool)

50372 EditableText’s autofocus:true should not crash (a: text input, cla: yes, f: focus, framework, severe: crash, waiting for tree to go green)

50377 Update samples to work with Dartpad, and convert all that make sense to use Dartpad (cla: yes, f: material design, framework, team, waiting for tree to go green)