75797 [flutter_releases] Update additional pub packages to stable for 1.26.0-17.4.pre (cla: yes, team, tool)

75798 Add mac/android smoke catalina test to dashboard (cla: yes, team, waiting for tree to go green)

75804 [flutter_releases] Flutter Framework 1.26.0-17.5.pre Beta Cherrypicks (cla: yes, engine, f: material design, framework, tool)

75807 [flutter_tools] refactor devtools handler to expose single method for run/attach and restart (cla: yes, tool, waiting for tree to go green)

75809 Apply bottom margin to FABs that have been boosted into the Safe Area (a: fidelity, a: quality, cla: yes, f: material design, framework, waiting for tree to go green)