67240 [flutter_tools] remove globals from IntelliJ validator, refactor tests to remove dependency on JAR (cla: yes, tool)

67242 [flutter_tools] Simplify plugin test cases and expand coverage of AndroidPlugin (cla: yes, tool)

67274 [flutter_tools] refactor local engine locator to its own class (cla: yes, tool)

67279 [flutter_tools] delete code related to reload method (cla: yes, tool)

67295 Handle missing Android SDKs in getEmulators() (cla: yes, tool, waiting for tree to go green)

67316 Remove goldens request timeout (cla: yes, tool, waiting for tree to go green)

67331 [flutter_tools] disable source maps by default for release builds, enable for run and with command line arg (cla: yes, tool)