83128 Additional flags for xcodebuild (tool, cla: yes, waiting for tree to go green)

83132 Use type:int without format in gen_l10n (tool, cla: yes, waiting for tree to go green)

83134 Be more helpful when l10n generation fails (tool, cla: yes, waiting for tree to go green)

83135 Move AndroidX error handler to the end (tool, cla: yes, waiting for tree to go green)

83137 Move globals.artifacts to globals_null_migrated, update imports (team, tool, cla: yes, waiting for tree to go green, a: null-safety)

83147 Migrate build_system, exceptions, and source to null safety (team, tool, cla: yes, waiting for tree to go green, a: null-safety)