Why is `LinearMap.IsPositive` using self-adjoint?

Stream: mathlib4

[Monica Omar]

Is there a reason why docs#LinearMap.IsPositive uses IsSelfAdjoint instead of IsSymmetric and without finite-dimensionality?
At this point, it's literally just docs#ContinuousLinearMap.IsPositive but with an additional hypothesis of finite-dimensionality. It's less general than if it were using IsSymmetric.

[Monica Omar]

I refactored the file: #27089
I really think we should do it this way rather than the way we already have it.