Annotation based cleanup on methods works only when flag name is same as specified in the config

[himanshuguptan]

Description:

Annotation-based cleanup looks for an exact string match on the flag name as specified in the build.gradle.
It doesn't look for the requisite enum name relationship for the specified flag name.
For example,
Case 1: Piranha:FlagName="STALE_FLAG", IsTreated = true,

public enum Experiment {
    STALE_FLAG("stale.flag"),
    OTHER_FLAG("other.flag");
    :
}

@FlagTesting(control = {"stale.flag"})
public void someMethod(...) {
  :
}

Expected: someMethod() gets deleted
Actual: someMethod() isn't deleted

---

Case 2: Case 1: Piranha:FlagName="stale.flag", IsTreated = true,

public enum Experiment {
    STALE_FLAG("stale.flag"),
    OTHER_FLAG("other.flag");
    :
}

@FlagTesting(control = {Experiment.STALE_FLAG})
public void someMethod(...) {
  :
}

Expected: someMethod() gets deleted
Actual: someMethod() isn't deleted

---

Root cause:

The likely issue is that we are simply comparing the xpFlagName value for equality with the annotation value (or one of the values in the annotation test list). While this works when both the config and the annotation usage use the same name: either the enum name or the feature flag string literal directly, it breaks in the other two possible combinations as shown above.

---

Fix:

Add a check where the xpFlagName not only matches the annotation value as only but either matches the value or the enum name as in the enum definition.
We could leverage a coding construct similar to these lines.

[ketkarameya]

@himanshuguptan can you please try to use polyglot piranha (under piranha/polyglot ) ?
This rule in polyglot Piranha kinda does what you want ?