tree f7d18c4226f5b639ebc61c858958b14192d0ba57
parent f0e7d3081d575f73882857a040eae60c736361ee
author Prudhvi Akhil Alahari <prudhvi.alahari@linaro.org> 1699002878 +0530
committer Prudhvi Akhil Alahari <prudhvi.alahari@linaro.org> 1699005032 +0530

Fix to not mark a valid preloaded subtask as INVALID

Before this change, a subtask was marked as INVALID when a task had a
preload-task pointing to a task from external file which had a
subtask [1]. While preloading a task, all the subtasks are copied to
the current task. Since the subtask property was a String, it does
not maintain the information regarding the location of the subtask.
Due to which, the plugin fails to lookup the subtask.

Thus, fix this issue by using TaskKey as the type for subtask property,
which helps in tracking the location of the subtask. Add tests for the
same.

[1]
file: `All-Projects:refs/meta/config:task.config`
```
[root "root task"]
    applicable = status:open
    preload-task = //common.config^simple task with subtask
```

file: `All-Projects:refs/meta/config:task/common.config`
```
[task "simple task with subtask"]
  applicable = is:open
  subtask = passing task

[task "passing task"]
  applicable = is:open
  pass = True
```

Change-Id: Iacf5345c575209267cf6ad0489327ee10feed55c