79500 Correct misspellings throughout the codebase (a: tests, cla: yes, f: cupertino, f: material design, framework, team, tool, waiting for tree to go green)

79501 [flutter_tools] Fix breakage when test main is tagged with @doNotStore (cla: yes, tool, waiting for tree to go green)

79504 Migrate android_studio to null safety (a: null-safety, cla: yes, team, tool, waiting for tree to go green)

79506 enterText to move the caret to the end (a: tests, cla: yes, f: material design, framework, waiting for tree to go green)

79507 Fix import device_port_forwarder typo (cla: yes, tool)

79514 Take screenshot when startup perf test fails to run (cla: yes, team, team: infra, waiting for tree to go green)