Add cmdline tools to docker image. (#82584)

* Add cmdline tools to docker image.

This is to make the flutter doctor new checks to pass.

Bug: https://github.com/flutter/flutter/issues/82565

* Use correct package name.

* Add version to sdkmanager command.

dev/ci/docker_linux/Dockerfile

@@ -82,6 +82,7 @@ RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "tools" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "build-tools;28.0.3" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "platforms;android-30" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "platform-tools" > /dev/null
+RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "cmdline-tools;latest" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "extras;android;m2repository" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "extras;google;m2repository" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "patcher;v4" > /dev/null