Fixes https://github.com/flutter/flutter/issues/10703

Eliminates the need for the device/daemon code to get at the iOS/Android
tooling indirectly via Doctor. In tests, we now inject the workflow
objects (or mocks) directly.

* add min version checks for IntelliJ

* validate the installed versions of IntelliJ and the flutter plugin

* review comments

Fixes https://github.com/flutter/flutter/issues/9954

Add a flutter doctor --android-licenses command that locates and runs the Android SDK license manager (#9892)

See https://github.com/flutter/flutter/issues/8438

Fixes https://github.com/flutter/flutter/issues/8690

* upgrade to linter-0.1.30

* add prefer_is_empty lint
* add directives_ordering lint
* add no_adjacent_strings_in_list lint
* add no_duplicate_case_values lint
* add prefer_collection_literals lint
* add prefer_const_constructors lint
* add prefer_contains lint
* add prefer_initializing_formals lint
* add unnecessary_null_aware_assignments lint
* add unnecessary_null_in_if_null_operators lint

* Use Java bundled with Android Studio for gradle

* review comments

- [x] Add custom logic on MacOS to determine if Java is installed before invoking `java`.
- [x] Check JAVA_HOME, platform specific logic, and finally PATH to locate the `java` executable.
- [x] Improved doctor messages.

Fixes #8508
Fixes #8521

The JDK doesn't put `javac` in the PATH on Windows :(

Line was accidentally removed by #8320

Also, change the version check from `java` to `javac` since we need the JDK and not just the JRE.

This reverts commit 70d7fe3a.

The Java version missmatch on the bots has been resolved.

* Teach flutter tools to find gradle

Flutter tools will now use Gradle from Android Studio, which is now found automatically.

flutter doctor will verify that Android Studio has been installed, and that the included Gradle is at least version 2.14.1.

It is still possible to manually configure the path to Android Studio (flutter config --android-studio-dir=XXX) or Gradle (flutter config --gradle-dir=XXX), but this should only be necessary if they're installed somewhere non-standard.

Only tested on Linux and macOS for now.

Fixes #8131

Required for https://github.com/flutter/flutter/issues/138

This ensures that accidental usages of dart:io's
file API don't creep in over time.

With this change, they're run via instance methods on an object
obtained through the context. This will allow us to substitute
that object in tests with replay/record versions to allow us to
mock out the os-layer in tests.

* show device list in flutter doctor output
fixes https://github.com/flutter/flutter/issues/5625

fix https://github.com/flutter/flutter/issues/2157